INTRODUCTION — A wide variety of lesions occurs on the vulva. Some of the disorders causing these lesions are limited to the vulva, while others also involve skin or mucocutaneous membranes elsewhere on the body. This topic provides a morphology-based classification system that can help clinicians with the differential diagnosis of these lesions after performing a history and physical examination. This classification system is also useful for guiding the choice of diagnostic tests and procedures.
This topic will focus on the differential diagnosis of yellow, skin-colored, and edematous vulvar lesions. Discussion of red, other pigmented, erosive and ulcerative, and white lesions are presented in related content.
●(See "Vulvar lesions: Differential diagnosis of red lesions".)
●(See "Vulvar lesions: Differential diagnosis of pigmented (black, brown, blue) lesions".)
●(See "Vulvar lesions: Differential diagnosis of vesicles, bullae, erosions, and ulcers".)
●(See "Vulvar lesions: Differential diagnosis of white lesions".)
The pertinent history, physical examination, and diagnostic tests and procedures used to evaluate patients with vulvar lesions are described separately (see "Vulvar lesions: Diagnostic evaluation"). Treatment is also discussed separately in topic reviews on these disorders.
MORPHOLOGIC DEFINITIONS FOR MUCOCUTANEOUS VULVAR LESIONS — Mucocutaneous vulvar lesions can be classified using the morphologic definitions described in the table (table 1).
DIAGNOSTIC EVALUATION
Practical tips — Based on the authors' experience, clinicians should be aware of the following points when evaluating dermatologic lesions of the vulva:
●Alternate appearance of vulvar lesions – Many skin conditions may appear differently on the vulva than on other parts of the skin as the vulva is so moist and the area is commonly subject to friction.
●Concomitant conditions – On the vulva, concomitant conditions are commonly present (eg, irritant contact dermatitis from the use of caustic soaps or over washing is commonly seen in individuals with vulvar lichen sclerosus).
●Impact of topical therapies – Vulvar conditions may be significantly altered by the use of topical treatments. The authors ask patients about use of prescription, over-the-counter, compounded, and alternative topical preparations.
●Role of biopsy – Be prepared to perform a biopsy, especially if a vulvar lesion is atypical, bleeding, the patient is immunocompromised, the lesion is not responding to appropriate treatment, or there is concern for a malignancy [1]. For any lesions with variable or irregular areas, more than one biopsy may be needed. At times, the biopsy results can be inconclusive. If there are ever concerns or questions about the biopsy report, it is important to speak with the pathologist.
●Consider possibility of systemic disease – Vulvar lesions can represent diseases that commonly present on the vulva (eg, herpes simplex virus) or systemic diseases that manifest in multiple sites including the vulva (eg, psoriasis). Providers are encouraged to ask patients with vulvar lesions about generalized symptoms and presence of lesions or skin changes on other body parts.
●Specialist referral – Patients whose symptoms do not respond, or worsen, despite usual treatment should be referred to a gynecologist, dermatologist, family medicine physician, or other health care providers who specialize in vulvar skin disorders.
How to use this topic — After a history, physical examination, and morphologic classification (table 1) have been performed, the information in this topic can be used to begin a differential diagnosis of the lesion. Diagnostic entities are listed for each morphologic classification and often listed under more than one morphologic classification since many lesions have more than one presentation (morphologic type, color). The complete description of the diagnostic entity is provided only once; for morphologic variants, the entity is noted and linked to its descriptive section.
This topic is an overview of yellow, skin-colored, and edematous dermatologic lesions of the vulva. Detailed text specific to each type of vulvar lesion is available separately, and links are provided throughout the text where available. Brief summaries of pertinent history, physical examination, and diagnostic tests and procedures are provided in this topic. Discussions of the presentation, evaluation, and diagnosis of vulvar lesions are described in detail separately.
●(See "Vulvar lesions: Diagnostic evaluation".).
●(See "Approach to the clinical dermatologic diagnosis".)
●(See "Skin biopsy techniques".)
YELLOW PAPULES AND PUSTULES — Papules are small (<1 cm), palpable lesions while pustules are pus-filled blisters that can be of any size (table 1). The differential diagnoses of yellow papules and pustules of the vulva are grouped into common, less common, and rare presentations (table 2). A review of pustules on other areas of the body is available separately. (See "Approach to the patient with pustular skin lesions".)
Common etiologies — While all of the diseases in this list often present as red lesions of various morphologies (table 3 and table 4), they also have common yellow variants when on the vulva, particularly in processes that include pustule formation (table 2). The relative frequency of each may vary based on the patient population and type of clinical practice (for example, such disciplines as gynecology, dermatology, or internal medicine). For common etiologies, the diagnosis is typically made with a combination of patient history and physical examination, and, at times, laboratory testing.
Candidiasis — While candidiasis often presents with red patches and plaques (picture 1), it can also appear as yellow or yellow-white pustules (picture 2).
●(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Candidiasis'.)
●(See "Candida vulvovaginitis: Clinical manifestations and diagnosis".)
Folliculitis — In addition to presenting with red papules and nodules (picture 3 and picture 4 and picture 5 and picture 6), the papules of infectious bacterial folliculitis may be white or yellow-white when they are capped by a pustule (picture 7). These lesions are seen on the mons pubis and labia majora, especially if there has been hair removal with shaving, waxing, etc. The folliculitis can also involve the buttocks. Retention of keratin can cause a white appearance in the papules in keratosis pilaris (picture 8 and picture 9), a noninfectious disorder seen on the buttocks and thighs.
●(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Folliculitis'.)
●(See "Infectious folliculitis".)
●(See "Keratosis pilaris".)
Furunculosis — The red papules and nodules of furunculosis may have a white or yellow summit when they come to a point and form a pustule or carbuncle (picture 10).
●(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Furunculosis'.)
●(See "Cellulitis and skin abscess: Epidemiology, microbiology, clinical manifestations, and diagnosis".)
Hidradenitis suppurativa — Hidradenitis suppurativa is in the differential diagnosis of red papules and nodules. However, when pustules or abscesses form in hidradenitis suppurativa, they are yellow to white (picture 11).
●(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Hidradenitis suppurativa'.)
●(See "Hidradenitis suppurativa: Pathogenesis, clinical features, and diagnosis".)
Epidermoid cyst — Epidermoid cysts are in the differential diagnosis of red papules and nodules (table 4), white papules and nodules (table 5), and skin-colored lesions (table 6). However, epidermoid cysts may have a yellow tint, especially when they occur in heavily pigmented skin (picture 12).
●(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Epidermoid cysts (inflamed)'.)
●(See "Vulvar lesions: Differential diagnosis of white lesions", section on 'Epidermoid cysts'.)
●(See "Overview of benign lesions of the skin", section on 'Epidermoid cyst'.)
Postradiation color changes — Following radiation therapy, the skin may become yellow in color. The diagnosis and cause for this type of color change are established on clinical examination together with a history of preceding surgery, particularly in association with radiation therapy. Generally, biopsy is not needed for this diagnosis; however, if there is a question on the cause of color change, a biopsy should be performed. (See "Radiation dermatitis".)
Less common etiologies
Molluscum contagiosum — Molluscum contagiosum commonly presents as red papules and nodules with central umbilication as well as skin-colored lesions (table 6). However, the papules of molluscum contagiosum may have a yellow tint on occasion.
●(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Molluscum contagiosum'.)
●(See "Molluscum contagiosum".)
Rare etiologies
●Vestibular mucinous cyst – The smooth-surfaced papules and small nodules of mucinous cysts are 0.5 to 2.0 cm in diameter, located within the vulvar vestibule. They are an anatomic abnormality or a blockage of the normal vestibular secretions. Usually skin colored, they can be yellow or blue (table 6). They are from an anatomic abnormality or a blockage of the minor, normal vestibular gland secretions. A clinical diagnosis can be suspected by visualization. A local incision allowing the jelly-like secretions to be seen can confirm the diagnosis. At times, excision is performed to remove the entire cyst. Inside of the cyst is the typical secretion.
●Fox-Fordyce disease is rare. It is an occlusion of the apocrine ducts with sweat retention. It is an extremely pruritic eruption of monomorphous, 1 to 2 mm, closely set, dome-shaped, follicular papules around the pubic hairs (picture 13). The papules may be yellow, red, tan, brown, or skin colored. Classically, the lesions are seen in a cobblestone pattern. Similar lesions may occur in the axilla. The onset of Fox-Fordyce disease is at puberty. The clinical diagnosis is based on the distinct appearance of this disorder, but confirmation can be obtained by biopsy. Differential diagnoses include condylomata acuminata, milia, and tiny molluscum contagiosum lesions. (See "Fox-Fordyce disease (apocrine miliaria)".)
●Pustular psoriasis is a rare variant of psoriasis vulgaris. The disease presents with small (1 to 10 mm) pustules studded throughout typical psoriatic red patches and plaques (picture 14). The pustules are fragile and quickly break down, leaving a collarette scale encircling the periphery (picture 15). It is unlikely that this condition would be confined to the vulva; usually, there is widespread involvement elsewhere. A diagnosis can often be made clinically, but confirmation can be obtained when bacterial cultures are negative. (See "Pustular psoriasis: Pathogenesis, clinical manifestations, and diagnosis".)
●Subcorneal pustular dermatosis has a similar appearance (picture 16) to pustular psoriasis, both clinically and histologically; however, it has a greater predilection for intertriginous distribution. Bacterial cultures are negative, and biopsy may be warranted. (See "Subcorneal pustular dermatosis".)
●Condylomata lata is the anogenital form of secondary syphilis. It appears as sharply marginated, smooth, flat-topped, 1 to 2 cm moist papules and small plaques. These lesions may be skin colored, white, pink, or yellow (picture 17 and picture 18). Differential diagnosis includes human papillomavirus infection, such as low-grade squamous intraepithelial lesion or high-grade squamous intraepithelial lesion, and squamous cell carcinoma. A clinical diagnosis can be suspected but will require confirmation by positive serologic testing for syphilis [2,3].
•(See "Syphilis: Epidemiology, pathophysiology, and clinical manifestations in patients without HIV".)
•(See "Syphilis: Screening and diagnostic testing".)
SKIN-COLORED PAPULES, NODULES, AND PLAQUES (MAY BE PINK ON MUCOSAE) — The differential diagnosis of skin-colored vulvar lesions is broad (table 6). Papules, nodules, and plaques are classified using the morphologic definitions described in the table (table 1).
Common conditions — The lesions below are commonly seen on the vulva and may present with a range of coloration. The relative frequency of each may vary based on the patient population and type of clinical practice.
Vestibular papillomatosis — Vestibular papillomatosis is in the differential diagnosis of red patches and plaques (table 3), but the small, 1 to 2 mm, closely set, soft, individual, tubular papules tend to match the color of the mucosal tissue of the vestibule (image 1). They range in number from a few scattered lesions to dozens. (See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Vestibular papillomatosis'.)
Skin tags (acrochordons) — These soft, elongated papules may be skin colored, tan, or brown (picture 19 and picture 20 and picture 21 and table 7).
●(See "Overview of benign lesions of the skin", section on 'Acrochordon (skin tag)'.)
Squamous intraepithelial lesions of the vulva — Vulvar squamous intraepithelial lesions (SIL) include low-grade SIL (LSIL), high-grade SIL (HSIL), and differentiated vulvar intraepithelial neoplasia (dVIN) (table 8) [4].
●LSIL – LSIL of the vulva includes flat condyloma and skin effects related to human papillomavirus (HPV) infection (table 8) [4]. True condylomata acuminata are stalk-like with a branched tip, skin colored, and flat topped. They are common warts that tend to be pink, red, brown, or black (table 7). They are also in the differential diagnosis of white lesions (table 5 and table 9).
●HSIL and dVIN – HSIL of the vulva is pink, red (table 3), brown, or black (table 7), whereas non-HPV-related dVIN is more often white (table 5 and table 9) or skin colored (table 8).
•(See "Vulvar squamous intraepithelial lesions (vulvar intraepithelial neoplasia)".)
Lichen simplex chronicus — The lichenified plaques of lichen simplex chronicus occur as the result of chronic rubbing and scratching. They may be red (table 3), white (table 5), or skin colored (picture 22). The skin feels thick, like leather.
●(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Lichen simplex chronicus'.)
Scar — Scars are most often skin colored but may be white (table 5). (See "Vulvar lesions: Differential diagnosis of white lesions", section on 'Scar'.)
Epidermoid cyst — Noninflamed, keratin-filled epidermal cysts are usually skin colored (picture 23) but may be white (table 5). Inflamed epidermal cysts are red (table 4).
●(See "Vulvar lesions: Differential diagnosis of white lesions", section on 'Epidermoid cysts'.)
●(See "Overview of benign lesions of the skin", section on 'Epidermoid cyst'.)
Less common conditions — While nevi, cysts, and abscesses are typically diagnosed by history and physical examination, the other etiologies often require biopsy to confirm the diagnosis. At times, a biopsy may be indicated to exclude malignancy.
Molluscum contagiosum — The dome-shaped, often umbilicated papules of molluscum contagiosum may be red (table 4), white (table 5 and table 9), or skin colored (picture 24).
●(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Molluscum contagiosum'.)
●(See "Molluscum contagiosum".)
Bartholin duct cyst — Cystic enlargement of the Bartholin duct due to occlusion results in unilateral skin-colored or red swelling of the vulva that mimics true vulvar edema. It may be asymptomatic or symptomatic. Rupture or infection of these cysts leads to unilateral erythematous inflammatory swelling (table 4).
Diagnosis is usually possible clinically because of the unilateral swelling and the finding that the labium minus overlies the middle of the swelling. The diagnosis can be confirmed by incision and drainage of the cyst contents. The cyst may become infected, forming a Bartholin duct abscess. If pus is present (Bartholin abscess), the purulent fluid should be sent for bacterial culture.
●(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Bartholin duct abscesses'.)
●(See "Bartholin gland masses".)
Intradermal melanocytic nevus — Intradermal nevi are often skin colored but may also be tan or brown (table 7). They can be acquired or congenital.
●(See "Acquired melanocytic nevi (moles)".)
●(See "Congenital melanocytic nevi".)
Squamous cell carcinoma — The nodules of squamous cell carcinoma may be red (table 4), white (table 5 and table 9), or skin colored.
●(See "Vulvar cancer: Epidemiology, diagnosis, histopathology, and treatment".)
Rare conditions — These lesions typically require a biopsy or additional testing to confirm the diagnosis.
●Vestibular mucinous cyst – Vestibular mucinous cysts are solitary, benign, soft, smooth-surfaced, domed, translucent papules or small 0.5 to 2.0 cm nodules filled with clear, viscous mucin and located in the vulvar vestibule. They are an anatomic abnormality or a blockage of the vestibular gland secretions. They are usually the pink color of the surrounding vestibular mucosal surface but may be either a very light blue or light yellow (table 2). The lesion is asymptomatic. A clinical diagnosis is possible in most cases. Incision, which allows the jelly-like mucinous material to extrude, confirms the diagnosis.
●Basal cell carcinoma – The lesions of pigmented basal cell carcinoma mostly occur on the labia majora in older women as solitary, usually skin-colored to pink and sometimes tan-to-brown papules, plaques, or nodules. Sometimes the surface is eroded or ulcerated. (See "Epidemiology, pathogenesis, clinical features, and diagnosis of basal cell carcinoma".)
●Hidradenoma papilliferum (mammary-like gland adenoma) is a rare adnexal mammary gland-like tumor on the anogenital area mostly in women. They are benign, smooth-surfaced, soft-to-firm, 0.5 to 1.0 cm, translucent, skin-colored, pink-red, or occasionally dark lesions on the labia [5]. (See "Cutaneous adnexal tumors", section on 'Hidradenoma papilliferum'.)
●Syringomas are benign neoplasms made up of sweat glands and sweat ducts. They are rare, 2 to 20 mm, skin-colored, asymmetrically distributed, smooth-surfaced papules that can be single or multiple (picture 25). They are mainly located on the labia majora. When large numbers are present, they may coalesce to form a larger, bumpy plaque. Pruritus is common [5,6]. (See "Cutaneous adnexal tumors", section on 'Syringoma'.)
●Fox-Fordyce disease is a rare, extremely pruritic, eruption of monomorphous, 1 to 2 mm, closely set, dome-shaped, follicular papules around the pubic hairs. The papules may be skin colored (picture 26), yellow, red, or brown. Similar lesions may occur in the axilla. The clinical diagnosis is based on the distinctive appearance of this disorder, but confirmation can be obtained by biopsy. Differential diagnosis includes folliculitis and tiny molluscum contagiosum lesions. (See "Fox-Fordyce disease (apocrine miliaria)".)
●Neurofibromas are benign, soft, skin-colored to tan nodules that may occur in the periclitoral area or labia majora. They may appear as solitary nodules or may be numerous and widely distributed when they develop as part of generalized neurofibromatosis type 1 (von Recklinghausen disease).
•(See "Overview of benign lesions of the skin", section on 'Cutaneous neurofibroma'.)
•(See "Neurofibromatosis type 1 (NF1): Pathogenesis, clinical features, and diagnosis".)
●Condylomata lata is the anogenital form of secondary syphilis. It appears as sharply marginated, smooth, flat-topped, 1 to 2 cm, moist papules and small plaques. These lesions may be skin colored, white, pink, or yellow (picture 17 and picture 18). The differential diagnosis includes HPV and HSIL of the vulva. A clinical diagnosis can be suspected but will require confirmation by positive serologic tests for syphilis.
•(See "Syphilis: Epidemiology, pathophysiology, and clinical manifestations in patients without HIV".)
•(See "Syphilis: Screening and diagnostic testing".)
SKIN-COLORED OR ERYTHEMATOUS EDEMA — Edema is a palpable swelling caused by expansion of interstitial fluid volume from a variety of causes (table 10). The differential diagnosis of vulvar edema, whether skin colored or erythematous, is broad (table 11). Edema may occur in isolation or with other lesions of varied colors and morphologies. Detailed discussions of pathophysiology, clinical manifestations, evaluation, and treatment of edema in adults are presented separately.
●(See "Pathophysiology and etiology of edema in adults".)
●(See "Clinical manifestations and evaluation of edema in adults".)
●(See "General principles of the treatment of edema in adults".)
Common causes — These entities are typically identified with a combination of patient history and physical examination. Biopsy may be required to differentiate Crohn disease from hidradenitis suppurativa. The relative frequency of each may vary based on the patient population and type of clinical practice (for example, such disciplines as gynecology, dermatology, or internal medicine).
Postsurgical and postradiation edema — Vulvar edema can follow any significant lymphatic vessel damage caused by surgery or radiation therapy of the lower abdomen and pelvic area. It initially presents as soft, easily pitted, skin-colored swelling of the labia minora and majora, but, if present for months to years, it will become more firm and less easily pitted. The diagnosis and cause for this type of edema are established on clinical examination together with a history of preceding surgery, particularly in association with lymphadenectomy or radiation therapy. Generally, biopsy is not needed for this diagnosis.
●(See "Clinical features and diagnosis of peripheral lymphedema", section on 'Cancer and cancer treatment'.)
Crohn disease — Crohn disease is in the differential diagnosis of red patches and plaques (table 3) and ulcerative disease (table 12). However, persistent vulvar edema can occur as a result of intestinal and/or vulvar Crohn disease. Edema may also be due to lymphatic disruption. Inflammatory lesions of Crohn disease do not have to be within, or even near, the site of the edema. Vulvar edema is one of the important signs of vulvar Crohn disease and can be seen in over 50 percent of cases. It can be unilateral or bilateral but is often diffuse, involving the labia majora and/or labia minora. When severe and chronic, there may be lymphedema and lymphangiectasias. The diagnosis of vulvar Crohn disease is often clinical. It can develop three to four years before the gastrointestinal disease. Consider the diagnosis of vulvar Crohn disease if there is chronic vulvar edema (due to lymphatic disruption), knife-cut ulcers (deep fissures in skin folds), aphthous ulcers, and/or perianal skin tags.
●(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Crohn disease'.)
●(See "Clinical manifestations, diagnosis, and prognosis of Crohn disease in adults".)
Hidradenitis suppurativa — Hidradenitis suppurativa is in the differential diagnosis of red patches and plaques (table 3) and very rarely ulcerative lesions (table 12). Persistent vulvar edema often occurs when lesions of hidradenitis suppurativa occur in the anogenital area. The inflammatory lesions can cause edema, even if they are some distance from the edema. Note that hidradenitis suppurativa and Crohn disease can be seen together in the anogenital area. (See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Hidradenitis suppurativa'.)
Edema due to pregnancy — Mild, skin-colored edema may occur in the late stages of pregnancy due to fetal pressure on the lymphatic vessels and is even more likely to occur in patients with preeclampsia. Postpartum vulvar edema can be a result of birth trauma and/or fluid shifts. The diagnosis is apparent when vulvar edema occurs in an otherwise well patient with preeclampsia [7]. (See "Overview of the postpartum period: Disorders and complications", section on 'Mild vulvar edema'.)
Edema due to active infection — Common vulvar infections that can present with vulvar edema include:
●Cellulitis – Active cellulitis of the vulva, usually due to Staphylococcus aureus or, less often, Streptococcus pyogenes, is accompanied by vulvar edema. The edema appears pink or red and may be painful and/or tender to palpation when infection is active. However, persistent, skin-colored edema may persist after active infections have subsided as a result of lymphatic destruction. (See 'Postinfectious edema' below.)
A diagnosis of cellulitis should be strongly considered when red, painful edema occurs in a patient with mild fever and malaise. Relapsing episodes of pink-to-red vulvar edema should also suggest cellulitis-related edema. The white blood cell count may be elevated. Bacterial cultures are not helpful. The diagnosis is confirmed if there is a good response to oral antibiotic therapy. The edema usually resolves after the first episode, but becomes more permanent with repeated bouts of cellulitis due to progressive lymphatic destruction. The persistent lymphatic edema makes the skin more susceptible to further infection with any minor trauma.
•(See "Cellulitis and skin abscess: Epidemiology, microbiology, clinical manifestations, and diagnosis".)
•(See "Acute cellulitis and erysipelas in adults: Treatment".)
●Primary herpes simplex virus (HSV) infection – Vulvar edema may also occur in the setting of primary HSV infection. The edema is usually erythematous, and the diagnosis is dependent on diagnosis of HSV. Following disease resolution, with or without treatment, the edema subsides.
•(See "Epidemiology, clinical manifestations, and diagnosis of genital herpes simplex virus infection".)
●Vulvovaginal candidiasis – With candidiasis, the edema is usually erythematous (picture 1), and the diagnosis depends on confirmation of Candida infection. Following treatment, the edema subsides.
•(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Candidiasis'.)
•(See "Candida vulvovaginitis: Clinical manifestations and diagnosis".)
•(See "Candida vulvovaginitis: Treatment".)
Less common causes — The entities below can cause vulvar edema but are less common causes (table 11). Vulvar edema is generally one component of the presentations below but may not be the primary skin change.
Postinfectious edema — Vulvar edema following an initial episode of bacterial cellulitis resolves. However, cellulitis damages the lymphatic system, and, following several recurrent episodes of cellulitis, noninflammatory vulvar edema becomes more permanent, leading to a locus minoris resistentiae and repeated episodes of cellulitis. This chronic edema is skin colored and gradually becomes firmer and pits less easily.
The diagnosis depends on obtaining a history of episodic redness and swelling. The diagnosis is further supported if the recurrent inflammatory episodes cease while the patient is taking long-term prophylactic antibiotics. Biopsy and attempts to culture pathogenic bacteria from the surface or from needle aspirates are not helpful.
Bartholin duct abscess — A Bartholin duct abscess is in the differential diagnosis of red papules and nodules (table 4). The inflammation associated with a Bartholin duct abscess causes unilateral vulvar edema, which subsides when the abscess is successfully treated. (See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Bartholin duct abscesses'.)
Allergic contact dermatitis — Vulvar contact dermatitis is in the differential diagnosis of red patches and plaques (table 3). However, the inflammation associated with vulvar contact dermatitis of the allergic type is associated with vulvar edema. It is usually itchy and subsides after appropriate treatment.
●(See "Vulvar lesions: Differential diagnosis of red lesions", section on 'Allergic contact dermatitis'.)
Trauma — Edema can arise after any significant blunt trauma to the vulvar tissue. Unless blood vessel damage occurs, causing purpura, the edema is skin colored, soft, and easily pitted. Usually, the diagnosis is apparent because of the short interval between the recognized trauma and the development of swelling. An exception is low-grade, chronic trauma that can occur from long-range bicycle riding or, more rarely, horseback riding [7]. Both of these activities can gradually develop chronic lymphatic damage with or without recurrent cellulitis.
Rare causes — The etiologies below are rare causes of vulvar edema. In addition to history and physical examination, a biopsy may be required to confirm the diagnosis.
●Acute allergic angioedema has a rapid, immunoglobulin E-mediated onset. It is most likely to impact the vulva when a patient has become sensitized to latex or semen. This edema is deep into the fat and lasts 24 to 48 hours. It may or may not be itchy and is more often tender and painful. The edema is usually skin colored, although sometimes pink. It is also soft, pitting easily with pressure to the skin. Angioedema at distant sites, such as the eyelids, lips, and airway, is also possible. The edema arises acutely and resolves spontaneously hours later. There are no skin surface changes like those seen in a typical allergic contact dermatitis. The allergic dermatitis diagnosis is suggested by the acute course of the edema and a history of contact with latex or semen within the previous minutes. Angioedema can be acute or chronic in the spectrum of urticaria and typically involves other skin areas. Of note, urticarial lesions are itchy, do not have deep swelling, are more transient, and last less than 24 hours. Allergic angioedema may be part of a wider systemic reaction to foods, drugs, or other causes.
•(See "Latex allergy: Epidemiology, clinical manifestations, and diagnosis".)
•(See "Allergic reactions to seminal plasma".)
●Localized lymphangioma can be congenital or acquired [8].
•Congenital lymphangiomas (also called lymphangioma circumscriptum) are due to faulty lymph vessel formation. The inguinal and genital area represents a fairly frequent site for these deep-seated analogs of hemangiomas. The lesions are usually plaques of small, grouped, firm, clear vesicles (picture 27). With trauma, they can be red and edematous from bleeding into the lymphatics.
•Acquired lymphangiomas most often occur following pelvic surgery or radiation therapy and are also seen with hidradenitis suppurativa, recurrent cellulitis, and Crohn disease. These are more widespread and scattered. There can be solid, firm nodules and warty papules. In both types of lymphangiomas, the overlying skin is normal. Later, due to a propensity for bacterial infection, damage occurs to the lymphatic tissue, causing chronic, firm, not easily pitted vulvar edema. Sometimes, dilated cystic structures form pseudo-blisters (lymphangiectasis) on the overlying skin (picture 28).
●Milroy disease is noted at, or shortly after, birth. Defects in lymph vessel formation result in lymphedema in one or both legs (table 13). Skin-colored, fairly firm vulvar edema may also develop. (See "Pathophysiology and etiology of edema in children" and "Pathophysiology and etiology of edema in children", section on 'Congenital lymphedema'.)
●Melkersson-Rosenthal syndrome is an idiopathic, skin-colored, fairly firm edema of the face (orofacial granulomatosis) and, on rare occasion, the vulva. Very few cases have been reported in which only the vulva is involved [9]. Most cases went on to develop Crohn disease. The diagnosis is established when granulomas, similar to those that occur in Crohn disease, are found on biopsy and there is no evidence of Crohn disease or sarcoidosis. (See "Bell's palsy: Pathogenesis, clinical features, and diagnosis in adults", section on 'Melkersson-Rosenthal syndrome'.)
●Rare infections – Lymphatic filariasis (elephantiasis) can rarely affect the vulva resulting in lymphedema. The cause is a tread-like round worm, usually Wuchereria bancrofti or Brugia malayi. It is spread by mosquitoes and found in subtropical Asia, Africa, South America, and parts of the Caribbean. In the same geographic areas, chronic lymphogranuloma venereum from Chlamydia trachomatis and granuloma inguinale from Klebsiella granulomatosis can cause significant vulvar edema.
•(See "Lymphatic filariasis: Epidemiology, clinical manifestations, and diagnosis".)
•(See "Lymphogranuloma venereum".)
•(See "Approach to the patient with genital ulcers", section on 'Sexually transmitted'.)
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Vulvar dermatitis".)
SUMMARY AND RECOMMENDATIONS
●Initial evaluation – For individuals with vulvar lesions, evaluation begins with a history, physical examination, and morphologic classification of the lesion (table 1), which allows formation of the differential diagnosis. (See 'Morphologic definitions for mucocutaneous vulvar lesions' above.)
●Clinical points – Based on the authors' experience, clinicians should be aware of the following points when evaluating dermatologic lesions of the vulva (see 'Practical tips' above):
•Alternate appearance of vulvar lesions – Many skin conditions may appear differently on the vulva than on other parts of the skin as the vulva is so moist and the area is commonly subject to friction.
•Concomitant conditions – On the vulva, concomitant conditions are commonly present (eg, irritant contact dermatitis from the use of caustic soaps or over washing is commonly seen in individuals with vulvar lichen sclerosus).
•Impact of topical therapies – Vulvar conditions may be significantly altered by the use of topical treatments. The authors ask patients about use of prescription, over-the-counter, compounded, and alternative topical preparations.
•Role of biopsy – Be prepared to perform a biopsy, especially if a vulvar lesion is atypical, bleeding, the patient is immunocompromised, the lesion is not responding to appropriate treatment, or there is concern for a malignancy. For any lesions with variable or irregular areas, more than one biopsy may be needed. At times, the biopsy results can be inconclusive. If there are ever concerns or questions about the biopsy report, it is important to speak with the pathologist.
•Consider possibility of systemic disease – Vulvar lesions can represent diseases that commonly present on the vulva (eg, herpes simplex virus) or systemic diseases that manifest in multiple sites including the vulva (eg, psoriasis). Providers are encouraged to ask patients with vulvar lesions about generalized symptoms and presence of lesions or skin changes on other body parts.
•Specialist referral – Patients whose symptoms do not respond, or worsen, despite usual treatment should be referred to a gynecologist, dermatologist, family medicine physician, or other health care providers who specialize in vulvar skin disorders.
●Yellow vulvar lesions – Yellow vulvar lesions include papules and pustules. Papules are small (<1 cm), palpable lesions while pustules are pus-filled blisters that can be of any size (table 1). The differential diagnoses of yellow papules and pustules of the vulva are grouped into common, less common, and rare presentations (table 2). (See 'Yellow papules and pustules' above.)
•Common – Common etiologies of yellow papules and pustules include vulvar candidiasis, folliculitis, furunculosis, hidradenitis suppurativa, epidermoid cyst, and postradiation color changes. While these entities often present as red lesions, yellow forms occur as well. Diagnosis is typically made by history and physical examination. (See 'Common etiologies' above.)
•Less common – Molluscum contagiosum is a less common etiology of vulvar lesions. (See 'Less common etiologies' above.)
•Rare – Rare etiologies of yellow vulvar lesions include vestibular mucinous cyst, Fox-Fordyce disease, pustular psoriasis, subcorneal pustular dermatosis, and condylomata lata. (See 'Rare etiologies' above.)
●Skin-colored papules, nodules, and plaques – The differential diagnosis of skin-colored vulvar lesions is broad (table 6). Papules, nodules, and plaques are classified using the morphologic definitions described in the table (table 1). (See 'Skin-colored papules, nodules, and plaques (may be pink on mucosae)' above.)
•Common conditions include vestibular papillomatosis, skin tags (acrochordons), vulvar squamous intraepithelial lesions (SIL; including low-grade, high-grade, and differentiated vulvar intraepithelial neoplasia), lichen simplex chronicus, scar, and epidermoid cysts. With the exception of the vulvar SILs, the diagnosis of these lesions is typically made by history and physical examination. (See 'Common conditions' above.)
•Less common conditions of skin-colored vulvar lesions include molluscum contagiosum, Bartholin duct cyst, intradermal melanocytic nevus, and squamous cell carcinoma. (See 'Less common conditions' above.)
•Rare conditions of skin-colored lesions include vestibular mucinous cyst, basal cell carcinoma, hidradenoma papilliferum, syringoma, Fox-Fordyce disease, neurofibroma, and condylomata lata. (See 'Rare conditions' above.)
●Vulvar edema – Vulvar edema may be skin colored or erythematous. The differential diagnosis of vulvar edema, whether skin colored or erythematous, is broad (table 11). Edema may occur in isolation or with other lesions of varied colors and morphologies. (See 'Skin-colored or erythematous edema' above.)
•Common causes of vulvar edema include postsurgical and postradiation changes, Crohn disease, hidradenitis suppurativa, and edema related to pregnancy or active infection. As with other common vulvar dermatoses, the patient's history and physical examination typically leads to the diagnosis.
•Less common causes of vulvar edema include postinfectious edema, Bartholin duct abscess, allergic contact dermatitis, and trauma. These entities typically present with other vulvar findings, of which edema may be one.
•Rare causes of vulvar edema include acute allergic angioedema, localized lymphangioma, Milroy disease, Melkersson-Rosenthal syndrome, and rare infections including filariasis, lymphogranuloma venereum, and granuloma inguinale. Biopsy and appropriate blood tests may be required to make these diagnoses.
ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Drs. T Minsue Chen, Aileen Langston, and Peter Lynch, who contributed to earlier versions of this topic review.
