Successful treatment of nodular scabies with long-lasting ivermectin dose schedule in an adult patient non responder to permethrin.

Scabies is a worldwide diffused ectoparasitic infestation of the skin by the mite Sarcoptes scabiei: classic scabies is the most common form while the nodular form is a rare clinical variant characterized by the highly itchy nodules and papules. This report describes the clinical approach of a case of late diagnosis of nodular scabies non responder to treatment with permethrin applied twice. Given the non-response, the decision was made to start ivermectin along with tacrolimus ointment. The lesions improved after the second ivermectin dose and pruritus disappeared; on the basis of the clinical history the drug schedule was tailored and a total of 17 doses were administered till the last follow-up visit (June 2025): no side effect was reported. Nodular lesions gradually disappeared leaving hyperchromic lesions occasional flared up with burning sensation and were treated on demand with topic aloe. This report suggests that a personalized and long-term ivermectin schedule can be successful in selected cases of nodular scabies with previous resistance to permethrin.