Diagnosis: Nummular (discoid) eczema
A 45-year-old male presents with pruritic, coin-shaped plaques on his lower legs that have persisted for several weeks. The lesions are well-defined, erythematous, and associated with significant itching, which has affected his quality of life. He has a history of similar skin conditions but has not sought treatment previously.
A 45-year-old male presents with a 6-week history of pruritic, coin-shaped plaques on both lower legs. Examination reveals well-defined, erythematous plaques with scaling and crusting in some areas. The lesions are symmetrical and vary in size from 1 to 5 cm. There are no signs of secondary infection or other skin conditions noted.Location: Predominantly on the lower legs.Lesion morphology: Coin-shaped, well-circumscribed plaques.Associated findings: Erythema, scaling, and itching.Distribution: Bilateral and symmetrical.Exclusion of other conditions: No history of atopic dermatitis or psoriasis.
The patient reports that the lesions began after he started using a new laundry detergent, which he suspects might be a trigger. He has a history of atopic dermatitis in childhood but has not experienced significant skin issues in recent years. He has not used topical corticosteroids or any other treatments for this condition. His family history is positive for eczema, and he works in a profession with frequent exposure to irritants.Onset: Lesions began approximately 6 weeks ago.Triggers: New laundry detergent, possible environmental irritants.Prior treatments: No previous treatments attempted.Relevant history: History of childhood atopic dermatitis.Family history: Positive for eczema in siblings.Social history: Works in a manufacturing environment with exposure to potential irritants.
Acute / First-Line ManagementTopical corticosteroids: High-potency corticosteroids (e.g., clobetasol propionate 0.05% ointment) applied twice daily to affected areas until control is achieved.Emollients: Regular use of emollients (e.g., petrolatum) to maintain skin hydration.Antihistamines: Oral antihistamines (e.g., cetirizine 10 mg daily) to help control pruritus.Workup and Diagnostic ConfirmationClinical diagnosis: Based on characteristic appearance and history.Patch testing: Consider if allergic contact dermatitis is suspected as a potential trigger.Skin biopsy: Rarely needed, but can be performed to rule out other dermatoses if diagnosis is uncertain.Long-Term ManagementMoisturizers: Daily application of emollients to prevent recurrence.Education: Patient education on avoiding known triggers and irritants.Regular follow-ups: Monitor for recurrence and adjust treatment as necessary.Consideration of phototherapy: In cases of recalcitrant lesions.
Contact dermatitis: Often presents with similar lesions but typically associated with a specific exposure history and may have vesicular components.Psoriasis: Characterized by well-defined plaques with silvery scales, often with a family history, but less likely to be coin-shaped.Atopic dermatitis: Usually presents with a history of itch and may show flexural involvement, differing from the more localized lesions in this case.Granuloma annulare: Presents as annular plaques, typically asymptomatic, and is often self-limiting.Seborrheic dermatitis: Typically affects the scalp and face with greasy scales rather than discrete plaques on the lower legs.Impetigo: Superficial bacterial infection that may present with crusting lesions, often with systemic symptoms.Fungal infections: Tinea corporis may mimic the appearance but usually presents with central clearing and scaling.Cutaneous T-cell lymphoma: Rare but can present with patches or plaques; often associated with systemic symptoms.
High-Yield PearlsCoin-shaped lesions: Nummular eczema is characterized by well-defined, coin-shaped plaques, which can be confused with other dermatoses.Itching: Pruritus is a prominent feature and can significantly impact the patient's quality of life.Triggers: Identifying and avoiding potential irritants or allergens is crucial in management.Emollients: Regular use of emollients is essential for long-term management and prevention of flare-ups.Topical corticosteroids: High-potency corticosteroids are effective for acute flares, but long-term use should be monitored.Understanding the chronic nature of nummular eczema and its triggers is key to effective management.
Tags: nummular eczema