Non-Classic (Surrepticius) Scabies Presenting as Erythematous Painful Palmar Pustules in an Octagenarian

Sarcoptes scabiei classically presents with pruritic burrows. In addition to finger and toe web lesions, the penis and scrotum of men, the breast and areola of women, and the buttocks and axillae of both gender are common locations for mite-associated lesions. Scabies surrepticius refers to mite-related lesions that are not classical in morphology and/or distribution; there are several subtypes of non-classic or atypical scabies. Scabies surrepticius not only occurs in immunosuppressed individuals, but also in infants and children, and in elderly patients. An elderly woman developed mite-related bilateral erythematous painful palmar pustules that were clinically suspicious for a primary neutrophilic dermatosis; she also had a concurrent bacterial infection. The diagnosis of surrepticius scabies was established after evaluation of the deeper levels of her tissue biopsy specimen demonstrated a mite in the epidermis. All of her symptoms and lesions resolved after treatment with oral and topical antiscabetic therapy, and systemic antibiotics. Since the clinical presentation of the mite-related lesions can mimic those of other dermatologic or systemic conditions, a high degree of suspicion for the diagnosis of mite infestation must be entertained. Therefore, the clinician should consider the possibility of scabies surrepticius in any patient who develops new cutaneous lesions that are not typical for a defined dermatosis or do not resolve or improve after treatment.