4-53
Differential Diagnosis
Bacterial furunculosis - no larvae in lesion
Deep fungal infection - KOH positive
Atypical mycobacterial infection - no larvae in lesion
Plan:
Treatment
Primary: Place occlusive material such as petrolatum, mineral oil, butter, or raw pork to cause the larvae to
exit the skin (also diagnostic).
Alternative: Surgical excision of the larvae may be required in some cases.
Patient Education
Prevention and Hygiene: Proper use of insect repellents and mosquito netting will decrease transmission.
Follow-up Actions
Evacuation/Consultation Criteria: Evacuation not necessary. Consult dermatology or infectious disease
as needed.
Skin: Onchocerciasis (River Blindness)
MAJ Joseph Wilde, MC, USAIntroduction: Onchocerciasis is a larial parasitic disease of humans caused by Onchocerca volvulus. Black
ies, the vectors of the disease, require fast-owing streams or rivers for reproduction. The worm affects
inhabitants of central Africa, Yemen, Central America, southern Mexico, and South America.
Subjective: Symptoms
Severe and diffuse pruritus which worsens with scratching; deep skin nodules; ocular symptoms (photophobia,
excessive tears, pain, blurred vision)
Objective: Signs
Using Basic Tools: Deep subcutaneous nodules on the scalp (in Central and South America) or over bony
protuberances (in Africa). Acute cases may present only with pruritus, which is often worse on the buttocks,
abdomen, and lower extremities. Chronic skin changes, such as lichenication and scarring, are seen in
long-standing cases.
Using Advanced Tools: Lab: CBC for eosinophilia.
Assessment: Diagnose with clinical ndings and travel to endemic areas.
Differential Diagnosis
Scabies - common in groin area and ngers
Insect bites - pruritus eases with scratching
Miliaria rubra - small papules and vesicles at opening of sweat glands
Plan:
Treatment
Primary: Ivermectin 100-200 mcg/kg single dose
Primitive: Excise nodules and examine (histologic examination) for adult worms
Patient Education
Prevention and Hygiene: Avoid river areas, especially riverbanks, in endemic areas. Maximize personal
protective measures (insect repellents and mosquito netting, etc.).