Differential Diagnosis for Erythema on Hand with a White Dry Papule
- Single most likely diagnosis
- Eczema (atopic dermatitis or contact dermatitis): The presence of erythema and a white dry papule is consistent with eczema, which often presents with dry, scaly skin and can be triggered by various factors including allergens or irritants.
- Other Likely diagnoses
- Psoriasis: Characterized by well-defined erythematous plaques with silvery scales, psoriasis can sometimes present with a similar appearance, especially if the scales are dry and white.
- Dermatitis herpetiformis: Although typically presenting with intensely itchy, blistering skin, some cases might show dry papules, especially in the healing phase.
- Keratosis pilaris: This condition causes small, rough patches on the skin, which can sometimes appear as white, dry papules, especially on the hands.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
- Cellulitis or abscess: Although less likely given the description of a white dry papule, any sign of erythema and swelling should prompt consideration of infectious causes, which can rapidly progress and become severe.
- Squamous cell carcinoma: Though rare, a persistent or changing lesion, especially in sun-exposed areas like the hand, warrants consideration of skin cancer.
- Rare diagnoses
- Pityriasis rubra pilaris: A rare skin disorder characterized by constant scaling, palmoplantar keratoderma, and sometimes erythematous patches, which could fit the description in some cases.
- Lichen planus: Typically presents with purplish, itchy, flat bumps, but can occasionally have a variant that resembles a white, dry papule, especially on the hands.
- Sarcoidosis: A condition that can cause skin lesions, among other symptoms, and might rarely present with erythema and papules on the hands.