Rash began with one lesion followed by tender, disseminated eruption; fevers spiked to 102°F. Test your visual diagnostic skills.
A 43-year-old woman presents to the dermatology clinic with complaints of a rash of one weeks’ duration. The first lesion started on the left breast (at right), then scabbed over. About 4 days later, fever, chills, neck pain, and headache abruptly started. The fevers spiked to 102°F. A tender rash then disseminated to involve the face, trunk, and extremities. She denies muscle or joint pain, vomiting, sore throat, diarrhea, or dysuria. The patient reports no other sick contacts.
She lives in an apartment in Brooklyn, New York, and denies recent travel. She works as a cook. She is monogamous with her male partner and lives with 2 children. The patient’s 2-year-old daughter has a similar lesion on her right thigh, but denies other symptoms. The patient had chickenpox in childhood and denies a history of herpes. On questioning, the patient reports that she had called an exterminator 2 weeks ago to deal with a “mouse problem.”
Physical exam is significant for an erythematous plaque with an eschar on one breast. Grey pustulovesicles on an erythematous base can be found on the dorsal hands (image at right), face, arms, legs, and flank. The oral mucosa is clear.
What disease do symptoms and lesions suggest?
Rickettsialpox (R. akari) is a disease transmitted by mites found on the common house mouse. When mice become scarce (such as after a visit by the exterminator), the mites will bite the less favorable human host. Following the mite bite, the organism locally proliferates and an eschar forms. Within 3 to 7 days, the patient experiences sudden-onset fever, chills, sore throat, headache, and photophobia. Regional lymphadenopathy draining the site of the eschar is common. The generalized rash follows within 2-3 days.
Without treatment, the illness is self-limited and resolves after about a week. Treatment with doxycycline until 2 days after symptom resolution is typically recommended (usually 5 to7 days). Extermination and clearing the living quarters is important. The patient’s daughter harbors a similar eschar and may become symptomatic and require treatment.