| Primary skin conditions |
| Skin barrier dysfunction: Netherton syndrome, ichthyoses |
| Inflammatory skin conditions: psoriasis, contact dermatitis (irritant or allergic) |
| Primary immunodeficiencies and treatment complications |
| Severe combined immunodeficiency |
| Wiskott-Aldrich syndrome |
| Hyper-IgE syndrome |
| Graft-versus-host disease |
| Primary metabolic conditions |
| Mineral or vitamin deficiencies: zinc (acrodermatitis enteropathica), pyridoxine, and niacin |
| Other |
| Skin infections: HIV-associated, impetigo, seborrheic dermatitis |
| Drug reactions |
| Malignancies: cutaneous T cell lymphoma, Letterer-Siwe disease |
