Diagnosis: Erythema multiforme (HSV-associated)
A 25-year-old male presents with targetoid lesions on his hands following a recent episode of herpes labialis. The lesions developed over three days and are associated with mild pruritus. The patient reports no significant past medical history or recent medication use.
A 25-year-old male presents with a 3-day history of targetoid lesions on the dorsal surfaces of his hands. The patient experienced a recent episode of herpes labialis, which began approximately one week prior. On examination, the lesions are well-defined with a central vesicle surrounded by erythema and a pale halo. There is no mucosal involvement, and the patient is otherwise healthy.Distribution: Primarily on the hands and forearms.Lesion morphology: Targetoid with concentric rings.Associated symptoms: Mild pruritus without systemic symptoms.History of HSV: Recent cold sore noted.Vital signs: Within normal limits; no fever.
The patient reports that the lesions began after an episode of cold sores, which he has experienced intermittently since adolescence. He denies any recent medication changes or new exposures. There is no significant family history of autoimmune diseases or skin disorders. He has not previously required treatment for similar skin findings.Onset: Lesions started 3 days ago.Triggers: Recent herpes simplex virus (HSV) outbreak.Prior treatments: No prior treatments for skin lesions.Past medical history: Unremarkable; no chronic illnesses.Social history: Non-smoker, no recent travel.
Acute / First-Line ManagementSymptomatic relief: Antihistamines (e.g., diphenhydramine 25 mg orally at bedtime) for pruritus.Topical corticosteroids: Clobetasol propionate 0.05% ointment applied to affected areas twice daily.Systemic therapy: Consideration of oral acyclovir 400 mg TID for 7 days if lesions persist or worsen.Workup and Diagnostic ConfirmationClinical diagnosis: Based on characteristic appearance and recent HSV infection.Serology: HSV serology may be performed to confirm recent infection if unclear.Skin biopsy: Rarely needed but can be considered if diagnosis is uncertain.Long-Term ManagementPreventive measures: Education on HSV management and potential triggers.Suppressive therapy: Consider long-term acyclovir 400 mg daily if recurrent episodes occur.Follow-up: Regular follow-up to monitor for recurrence or complications.
Fixed Drug Eruption: Characterized by well-defined, round lesions that recur at the same site after drug exposure, often with a history of medication use.Stevens-Johnson Syndrome: Severe mucocutaneous reaction with widespread lesions and systemic symptoms; often associated with medications.Drug-Induced Hypersensitivity Syndrome: Systemic reaction with fever, lymphadenopathy, and skin lesions, typically following drug exposure.Psoriasis: Presents with well-demarcated plaques, often with silvery scales, and may involve the scalp and nails.Dermatitis Herpetiformis: Associated with gluten sensitivity, presents with vesicular lesions and intense pruritus, often on extensor surfaces.Urticaria Multiforme: Characterized by wheals and target-like lesions, often related to allergic reactions, but less well-defined than in this case.Acute Eczematous Dermatitis: May present with vesicles and weeping lesions, typically with a history of allergen exposure.Granuloma Annulare: Presents as annular lesions with central clearing, commonly seen in younger patients, often asymptomatic.
High-Yield PearlsTargetoid lesions: Characteristic of various conditions, including but not limited to erythema multiforme; clinical context is crucial.HSV association: Erythema multiforme can be triggered by herpes simplex virus, often following an active outbreak.Management: Focuses on symptomatic relief and addressing the underlying cause; acyclovir is effective in HSV-related cases.Skin biopsy: Generally unnecessary when clinical features are classic; reserved for atypical presentations.Education: Emphasizing HSV management can prevent future episodes of skin lesions.Recognition of the clinical pattern and associated triggers is key to effective management of erythema multiforme.
Tags: erythema multiforme, HSV