Pink pigtail in a skin biopsy: What is your diagnosis?

UNLABELLED

Sarcoptes scabiei is an obligate ectoparasite, which burrows into the stratum granulosum of the epidermis and lays its eggs. The resultant host inflammatory response leads to intensely pruritic papules.

CASE SYNOPSIS

A 63-year-old man undergoing treatment for immunoproliferative disease was suspected of having a pruritic drug eruption. Subsequent skin biopsy revealed an intracorneal burrow containing three pink, refractile pigtail-like structures, believed to be empty eggshells of S. scabiei.

CONCLUSION

Traditionally, the presence of adult mites or eggs in skin scrapings or a skin biopsy is required for a definitive diagnosis of scabies. However, our case and similar cases suggest that the diagnosis of scabies can also be made on the basis of pink pigtail-like structures, remnants of eggshells, within the intracorneal burrow.