Crusted scabies in a patient with lepromatous leprosy

Crusted scabies (CS) is a very contagious rare skin infestation caused by Sarcoptes scabiei var hominis, an obligate human parasite, transmitted by skin-to-skin contact.¹ Clinically, it can present with psoriasiform skin lesions in acral distribution with variable whitish scaling. It usually involves the subungueal area with nail hyperkeratosis and dystrophy.² A 56-year-old man, alcoholic, presented with a seven-month history of pruritus (with nocturnal exacerbation), weight loss and muscle weakness. The patient is a known case of lepromatous leprosy (LL), diagnosed 22 years ago with irregular treatment, neurological damage and deformities. On examination, hyperkeratosis with crusted lesions on hands and feet with severe nail dystrophy. We also noted an erythematous scaling eruption in the face, neck, scalp, trunk, and arms (Fig. 1). Laboratory results included a negative HIV and HTLV-1 tests, skin scraping revealed the mite and skin smear showed a bacteriological index of 6+. The patient started multidrug therapy for multibacillary leprosy and oral antihistamines, keratolytics, topical permethrin (5%), and repeated doses of ivermectin (200 μg/kg) on the 1st, 2nd, 8th, 9th, and 15th day. CS is a highly contagious rare variant of scabies and is frequently found in immunocompromised patients, mentally retarded, or physically incapacitated individuals.³ Infested individuals and their close contacts should be treated at the same time, even if asymptomatic.¹ There are few reported cases showing the association between CS and LL. In Brazil, due to the high number of leprosy, physicians should be aware of the possibility of CS in leprosy patients who develop widespread hyperkeratotic eruptions.

Fig. 1
Clinical manifestations of crusted scabies infection (A)–(C) Hyperkeratotic dermatosis with an acral distribution and nail dystrophy; (D) disseminated excoriations, crusts and scaling in the back; (E) and (F) leonine facies, pruritus and scaling, also crusts in the ear; (G) microscopic section of S. scabiei mite showing six legs and the bite apparatus.

Authors’ contributions

Alexandra Peres Paim Pedra e Cal, Cassio Porto Ferreira and José Augusto da Costa Nery contributed to clinical care and paper preparation.

Conflicts of interest

The authors declare no conflicts of interest.

References

• ¹
  Chosidow O. Scabies and pediculosis. Lancet. 2000; 355:819-26
• ²
  Hengge U.R, Currie B.J, Jäger G, Lupi O, Schwartz R.A. Scabies: a ubiquitous neglected skin disease. Lancet. 2006; 6:769-79
• ³
  Barbosa A.A.J, Silva T.M, Santos M.I, et al. Coexistence of an unusual form of scabies and lepromatous leprosy. A case report. Pathol Res Pract. 1996; 192:88-90

Publication Dates

• Publication in this collection
  Jul-Aug 2016

History

• Received
  12 Apr 2016
• Accepted
  18 Apr 2016