| Allergic contact dermatitis | More intense pruritus; signs of eczema in other body locations; positive patch tests |
| Irritant contact dermatitis | More intense pruritus; signs of eczema in other body locations |
| Atopic dermatitis | More intense pruritus; coexisting atopic diseases (e.g., asthma, rhinitis) or family history of atopic diseases; wool intolerance; often in antecubital and popliteal fossae |
| Seborrheic dermatitis | Erythematous scaly patches on the scalp; dandruff |
| Psoriasis vulgaris inversa | Psoriasiform lesions elsewhere on the body (especially on the scalp, elbows, knees, and sacral area); typical nail changes (e.g., pitting, “oil spots,” nail dystrophy) |
| Vitamin deficiency | Other signs of hypovitaminosis (e.g., phrynoderma) |
| Pemphigus vegetans | Coexisting erosions and blisters on skin or mucosae; circulating antibodies of pemphigus type; histopathology with positive immunofluorescent examination |
| Hailey-Hailey disease (familial benign chronic pemphigus) | Small blisters at the edge of the lesions; palmoplantar keratoderma and longitudinal nail stripes may occur |