Morbilliform drug eruption

Diagnosis: Morbilliform drug eruption

Symmetric erythematous macules and papules(maculopapular rash) on the trunk

Clinical Presentation

Symmetric erythematous macules and papules(maculopapular rash) on the trunk

Clinical History

Submitted by Alaa Saad. Originally posted September 12, 2010.

Treatment

See case discussion.

Differential Diagnosis

• Viral exanthem • Measles • Drug reaction with eosinophilia and systemic symptoms (DRESS) • Secondary syphilis • Acute HIV seroconversion • Guttate psoriasis • Pityriasis rosea

Key Learnings

• Most common type of cutaneous adverse drug reaction (~75% of all drug eruptions) • Exanthematous, maculopapular rash typically starting on trunk 7-14 days after starting a new drug • Classic "ampicillin rash" in EBV infection (80-100% incidence) • Must distinguish from DRESS: eosinophilia, liver/renal involvement, lymphadenopathy = red flags • Usually resolves within 1-2 weeks of drug withdrawal • Common culprits: beta-lactams, sulfonamides, allopurinol, anticonvulsants, NSAIDs • Challenge: rash may develop after course is completed or during an ongoing course

Tags: morbilliform, drug, eruption, alaa saad