INFECTED SCABIES

Diagnosis: INFECTED SCABIES

Case submitted by Dr.Azeem Alam Khan to the dermRounds community.

Clinical Presentation

Clinical photograph(s) submitted for peer review and discussion.

Clinical History

Submitted by Dr.Azeem Alam Khan. Originally posted September 29, 2009.

Treatment

See case discussion.

Differential Diagnosis

• Atopic dermatitis • Contact dermatitis • Insect bites • Dermatitis herpetiformis • Prurigo nodularis • Bullous pemphigoid • Drug eruption

Key Learnings

• Caused by Sarcoptes scabiei var. hominis — obligate human parasite • Pruritus is an allergic reaction to mite proteins — may take 2-6 weeks to develop in first infection • Pathognomonic finding: burrow (S-shaped or linear tunnel) in web spaces, wrists, elbows • Crusted (Norwegian) scabies: massive mite burden in immunocompromised — highly contagious • Treat all household contacts simultaneously even if asymptomatic • Post-treatment pruritus may persist for 2-4 weeks — does not indicate treatment failure • Dermoscopy: "delta wing" or "hang glider" sign (triangular, brown structure = mite head) • Nodular scabies: persistent pruritic nodules (hypersensitivity reaction) may persist for months after treatment

Tags: infected, scabies, dr.azeem alam khan