Case description
A 23 year-old man complained of a 6 month history of generalized pruritus and hyperkeratotic, crusted, fissured and scaly plaques localized in axillary folds, back, periumbilical skin and flexor surface of the knees (Figure 1). He also had multiple erythematous papules and excoriations due to scratching in trunk and extremities. Microscopic examination of skin scraping revealed multiple mites, confirming the diagnosis of crusted scabies ( Figure 2). Permethrin and ivermectin were administered, but during hospitalization day 3 the patient presented fever (38°) and numerous non follicular pustules over erythematous plaques on trunk and extremities. A biopsy was performed and findings were consistent with acute generalized exanthematous pustulosis (AGEP). Ivermectin was discontinued and permethrin regimen was completed with satisfactory evolution after 2 weeks (Figure 3 ).
Even though ivermectin is not FDA-approved for this use, in June 2019 the WHO added ivermectin to the 21st WHO Essential Medicines List. AGEP is not a common adverse effect of ivermectin. As Scabies remains a public health priority globally, this case highlights the importance of knowing possible reactions to frequently used medications and of novel therapeutics that serve as alternatives when it comes to scabies management.
Conflicts of interest: None declared.