Dengue fever: diagnostic importance of a camelback fever pattern

We present a case of imported dengue fever in a 52-year-old man acquired during a recent trip to Ecuador. Fever in a returning traveler from tropical areas often presents a diagnostic problem for clinicians. Our patient presented with severe arthralgias and myalgias and had a camelback/saddleback fever pattern accompanied by relative bradycardia, which was a clue to the diagnosis. He had conjunctival suffusion and the truncal rash, but adenopathy was not present. He also had a generalized headache and abdominal pain. Nonspecific laboratory abnormalities included leukopenia, lymphopenia, atypical lymphocytes, thrombocytopenia, and mildly increased serum transaminases. Clinicians should consider dengue fever in the differential diagnosis in travelers returning from dengue fever endemic areas of Southeast Asia, Latin America, and Africa. Although early findings are nonspecific, a truncal rash accompanied by leukopenia and thrombocytopenia, if followed by biphasic fever pattern (ie, camelback/saddleback fever curve with relative bradycardia), suggest dengue fever as the primary diagnostic consideration.