Common differential diagnoses.
| | | | Eczema variant | | Differential diagnosis |
| | Scalp and hair | | Seborrhoeic dermatitis: Fine scaling (yellow/ greasy) on scalp with mild erythema. Tending to confluence. | | Psoriasis: Thick scaling and erythema extending to hairline and ears. Hair thinning may occur. Tending to discrete paths with clear skin in between. |
| | Face and neck | | Atopic eczema: Eczematous areas especially of face show erythema, scaling and oozing, but much of non-eczematous skin may be very dry. | | Infantile seborrhoeic eczema: Greasy yellow-brown scales or crusting on scalp, face and napkin area with mild erythema. May not itch. |
| | | Airborne contact dermatitis: Erythema, blisters and weeping. | | Chronic actinic dermatitis (Photosensitivity): Acute erythema on sun-exposed area. |
| | | Acute eczema: Erythema, vesicles, oozing and crusting. Always itches, hence is scratched. | | Erysipelas/cellulitis: Intense erythema and oedema. |
| | Palms and soles | | Chronic dermatitis: Dryness, mild erythema, cracks and fissures. | | Chronic psoriasis: Thick scaling with silvery scales and erythema, often in discrete patches. |
| | | | Pompholyx eczema: Vesicles, bullae and weeping. | | Palmoplantar pustulosis: Dryness, yellow sterile pustules which resolve to brown macules. |
| | Dorsum hands | | Allergic hand eczema: Intense erythema, vesicles and blisters. | | Chronic irritant eczema: Dryness, mild erythema, cracks and fissures. |
| | Generalised | | Discoid eczema: Circular lesions, dry skin, moderate erythema. Very itchy. | | Psoriasis: Thick scaling with silvery scales and erythema. |
| | | Atopic eczema: Dryness, erythema, scaling with patchy oozing and marked scratching. Lichenification is increased line markings of the skin and pigmentation due to persistent scratching and rubbing.
| | Dermatitis herpetiformis: Small to medium vesicles on an erythematous and eczematized background – favours shoulder, knees and elbows. |
| | | Acute eczema: Erythema, vesicles, oozing and crusting. | | Bullous pemphigoid: Large tense bullae on an erythematous and eczematized background. |
| | | Chronic eczema: Dry skin, background of erythema, excoriation and lichenification. | | Tinea (excluding palms and soles): Erythema, mild scaling with a raised advancing edge and clearing centre. |
| | Flexural/perineal/
genital | | Flexural eczema: Dryness, erythema, minimal scaling or oozing. Satellite lesions. | | Flexural psoriasis: Erythema, minimal scaling, plaque forms and bilaterally symmetrical, less likely to be scratched.
Tinea cruris: Erythema, minimal scaling and unilateral. |
| | Limbs | | Atopic eczema: Dryness, erythema, scaling and vesicles. | | Keratosis pilaris: Follicular papules, skin coloured or brown, no erythema. |
| | | | Asteatotic eczema (craquele): Large dry flaky scales (‘crazy-paving appearance’), mild erythema | | Venous eczema: Erythema, decolourisation (due to haemosiderin) and scaling with associated oedema, ulceration and fibrosis. |
