Subungual and ungual scabies: avoiding severe presentation in high-risk patients

Scabies is a pruritic disorder caused by Sarcoptes scabiei var. hominis infestation of the skin. Transferred by close body contact, scabies is endemic within nursing homes and among poor and overcrowded populations. Crusted scabies is a severe form of disease, characterised by a large, thick, crusted eruption with significant mite infestation. We report a patient hospitalised with crusted scabies that had massive nail involvement. A 79-year-old female patient with multiple comorbidities and several recent prior scabies diagnoses presented with agitation and dystrophic fingernails; scabies mites were found embedded in and below the nail keratin. Aggressive treatment resulted in complete resolution, with notable improvements in mental status. Crusted scabies with nail involvement is extremely rare and may be more likely to develop from initially subclinical infestation sites. It is important to consider this potential presentation, as standard topical treatments may prove ineffective when there is deep nail involvement.