Which finding most suggests body lice infestation rather than head lice infestation?

Which finding most suggests body lice infestation rather than head lice infestation?

• A. Itching of scalp
• B. Excoriated macules along collar and underwear lines
• C. Inflammation on the face
• D. Linear or S-shaped lesions in webs of fingers and sides of hands

Answer: (B)

Bites from body lice tend to occur where clothing contacts the skin, especially along the collar, cuffs, waistband, and underwear seams, because these lice live in clothing and feed on the skin at those sites. The resulting excoriated macules in these areas reflect this clothing-associated distribution. In contrast, head lice stay on the scalp and cause itching there, often with nits along hair shafts, and the other findings listed point more toward alternate conditions (face inflammation isn’t typical for lice, and linear or S-shaped lesions between the fingers are characteristic of scabies). So the presence of excoriated macules along collar and underwear lines most strongly indicates body lice infestation.

Bites from body lice tend to occur where clothing contacts the skin, especially along the collar, cuffs, waistband, and underwear seams, because these lice live in clothing and feed on the skin at those sites. The resulting excoriated macules in these areas reflect this clothing-associated distribution. In contrast, head lice stay on the scalp and cause itching there, often with nits along hair shafts, and the other findings listed point more toward alternate conditions (face inflammation isn’t typical for lice, and linear or S-shaped lesions between the fingers are characteristic of scabies). So the presence of excoriated macules along collar and underwear lines most strongly indicates body lice infestation.