Erythema multiforme (EM) is an acute,immune-mediated skin reaction most frequently associated with herpes simplex virus (HSV) infection or, less commonly,with medications. Its polymorphic presentation, characterized by erythematous or vesiculobullous lesions, often leads to diagnostic confusion in primary care,particularly when mimicking drug eruptions or fungal infections. This case highlights the importance of clinical reasoning and multidisciplinary coordination in the evaluation of recurrent EM triggered by HSV infection.A 42-year-old woman presented with a 4-day history of erythematous, non-pruritic, target-like lesions predominantly on the upper limbs and face.She had been under empirical treatment with itraconazole and bilastine at home without improvement. The patient reported previous similar episodes approximately eight months and six months earlier. Physical examination showed erythematous and partially vesicular lesions with some painful evolution but no systemic symptoms.Vital signs were stable.Initial management included intramuscular methylprednisolone 80 mg, achieving partial improvement.After dermatology consultation, the lesions were identified as erythema multiforme, most likely related to herpes simplex virus infection.Oral valaciclovir and topical corticosteroids were prescribed, with complete resolution within days.This case emphasizes the diagnostic difficulty of distinguishing EM from drug-induced eruptions or infectious dermatoses in primary care.The recurrent nature,clinical morphology,and response to antiviral therapy supported a viral etiology.It demonstrates how misinterpretation of EM as mycosis or allergic reaction can delay definitive treatment and increase unnecessary exposure to antifungals or corticosteroids.Family physicians should consider herpes-associated EM in cases of recurrent erythematous or vesicular eruptions unresponsive to conventional antifungal or antihistaminic treatment. Establishing the viral etiology allows for targeted management, preventing misdiagnosis and unnecessary pharmacologic interventions.Recognition of herpes-associated EM requires awareness of its recurrent and polymorphic nature.In primary care,a careful clinical history and observation of lesion evolution are key to identifying the underlying cause.Early antiviral therapy can shorten the duration of outbreaks and reduce recurrence frequency,improving patient quality of life.This case also highlights the value of close communication between primary care and dermatology for diagnostic confirmation.Recurrent herpes-related erythema multiforme represents a diagnostic challenge in primary care.This case underscores the relevance of continuous clinical reassessment,appropriate specialist referral,and antiviral management to achieve optimal outcomes.