In a pediculosis capitis infestation, what is likely to be found on physical examination along with live lice?

In a pediculosis capitis infestation, what is likely to be found on physical examination along with live lice?

• A. Excoriated macules along the collar and underwear lines
• B. Inflammation and pustules on the face and neck
• C. Itching of the scalp, with skin excoriation on the back of the head
• D. Linear or S-shaped lesions in webs of fingers and sides of hands

Answer: (C)

Head lice infestation most commonly causes itching of the scalp due to sensitivity to louse saliva, and this itching often leads to scratching with resulting skin excoriations on the posterior scalp and neck. When live lice are present, this combination of scalp pruritus and excoriations at the back of the head is the classic exam finding, since the occipital region is a typical resting site for lice on the head. The other patterns described align with different conditions—body lice tend to cause lesions along clothing lines, facial pustules aren’t typical for head lice, and linear burrows between the fingers suggest scabies. So, itching with excoriations on the back of the head fits pediculosis capitis best.

Head lice infestation most commonly causes itching of the scalp due to sensitivity to louse saliva, and this itching often leads to scratching with resulting skin excoriations on the posterior scalp and neck. When live lice are present, this combination of scalp pruritus and excoriations at the back of the head is the classic exam finding, since the occipital region is a typical resting site for lice on the head. The other patterns described align with different conditions—body lice tend to cause lesions along clothing lines, facial pustules aren’t typical for head lice, and linear burrows between the fingers suggest scabies. So, itching with excoriations on the back of the head fits pediculosis capitis best.