A 42-year-old man presents to his physician with fever, headache, and rash. Three days ago, he developed fever and a headache, which minimally improved with acetaminophen. This morning he noticed a rash on his wrists and ankles that spread to his torso. He has no past medical history and does not smoke. He recently returned from a camping trip in Virginia 1 week ago. On examination, he is febrile and there are scattered erythematous blanching macules over his arms, legs, and torso.
What should be done next in the management of this patient?
A. Administer doxycyclineAdminister doxycycline. Rocky Mountain spotted fever is caused by the bacterial species Rickettsia rickettsii, which is carried by the Dermacentor variabilis tick. Though infection may occur in many areas of the United States, it is most common in the Southeastern United States. The incubation period is typically around 1 week, after which nonspecific symptoms of fever, headache, and myalgias develop. A few days later, a maculopapular rash appears that starts on the wrists and ankles (also commonly affects the palms and soles) and spreads to the trunk; it often evolves into a petechial rash. There is a high morbidity and mortality of this infection if it goes untreated, therefore doxycycline should be given empirically if the disease is suspected. (C) Testing for serum antibodies to Rickettsia will not be positive until about a week, which is too late; therefore, the diagnosis is usually confirmed with skin biopsy. (B) Rickettsiae infect the vascular endothelium, causing vascular damage and petechiae that may mimic a vasculitis; however, the recent travel and time course of the illness should lead the reader to suspect this infection and treat empirically with doxycycline. (D) Penicillin G is the treatment for syphilis, which can present with a maculopapular rash affecting the palms and soles (secondary syphilis). The patient’s recent hiking trip in Virginia makes infection with Rickettsia more likely. (E) Topical clobetasol is a powerful corticosteroid that may be used in cases of contact dermatitis, which can vary in appearance but often cause a vesicular eruption without systemic symptoms. (Note: Other important cases of a rash affecting the palms and soles include secondary syphilis and coxsackie virus; there are others, but these are the most commonly tested.)