Scabies
Scabies is a highly contagious infestation caused by the mite Sarcoptes scabiei var. hominis. It is transmitted via direct skin-to-skin contact or through fomites (clothing/bedding) in heavy infestations.
Clinical Presentation
- Intense Pruritus: Classically worse at night.
- Burrows: Pathognomonic thin, wavy, grayish-white, thread-like lines; most commonly found in the web spaces of fingers, wrists, and genitalia.
- Generalized Rash: Often presents as excoriated papules; hypersensitivity to the mite, eggs, and feces.
Diagnosis & Management
| Aspect | Details |
|---|---|
| Diagnosis | Microscopic identification of mites, eggs, or feces from a skin scraping of a burrow. |
| Treatment | Permethrin 5% cream (first-line); Oral Ivermectin for difficult or institutionalized cases. |
High-Yield Exam Pearl:
- Contact Management: Treat all household contacts and sexual partners simultaneously, even if they are asymptomatic, to prevent re-infestation.
- Crusted (Norwegian) Scabies: A severe form seen in immunocompromised individuals; characterized by thick, hyperkeratotic crusts containing thousands of mites. It is highly contagious and requires aggressive, combined treatment (Topical Permethrin + Oral Ivermectin).