Page 159 - Medical Parasitology_ A Textbook ( PDFDrive )

152 13 Ectoparasites of Medical Importance

Fig. 13.1 Adult of Sarcoptes scabiei
Pathogenesis and Clinical Features
The common sites for cutaneous lesions are the interdigital spaces, flexor surfaces
of the wrists and forearms, elbows, axillae, inguinal region and genitalia. The main
symptom is itch. The lesions appear as slightly reddish elevated tracks in the skin.
Intense itching, aggravated by sweat causes scratching which spread the infestation
and causes secondary bacterial infection. As a result, multiple papular, vesicular and
pustular lesions may be produced.
Crusted or Norwegian scabies is seen in patients with AIDS.
It is highly contagious with huge numbers of mites. Pruritus may be minimal or
absent.

Diagnosis
The types of lesion, itching and rash are suggestive of scabies.

1. Microscopic Examination
Demonstration of the mite, eggs, or faecal material after scraping or teasing the
lesion with the tip of a scalpel blade or a sterile needle.

Treatment
1. Permethrin 5%, cream/lotion
2. Lindane 1%, lotion/cream
3. Crotamiton 10%, ointment