New Pruritic Eruption with Unclear Trigger

Clinical History

34-year-old female with widespread pruritic eruption on the trunk and proximal extremities over two weeks. Small raised pink papules, intense itching, worse at night. No new meds, no travel, no known exposures. Lives with partner and two kids. She works at an assisted living facility. No household contacts with symptoms.

Clinical Question

I can’t pin down a trigger. History doesn’t suggest contact dermatitis or a drug reaction. What should I be thinking about before sending to derm?

Specialist Guidance

‍Based on the history and images, you need to rule out scabies. The papular morphology, truncal distribution, and nocturnal itching are all consistent, and her work in an assisted living facility is a significant exposure risk. The absence of household symptoms doesn’t rule it out, as contacts can be asymptomatic or pre-symptomatic.

I would recommend empiric treatment of the patient and all household members with permethrin 5% cream, neck down, leave on 8–14 hours, repeat in one week. Treat everyone in the household simultaneously, even if asymptomatic. Failure to treat contacts is the most common reason treatment fails. Hot wash all bedding and clothing. If two full cycles don’t clear it, then consider skin scraping or derm referral. Hydroxyzine 25mg at bedtime for the nocturnal itching. No biopsy needed.

Outcome

‍Patient and all household contacts treated with permethrin. Cleared after second application. One child later developed mild symptoms, confirming the diagnosis. Managed entirely in primary care. No referral required.

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