Human immunodeficiency virus primary infection
PHI syndrome is believed to occur in 50%-66% of newly infected individuals. Symptoms are variable; fever, headache, lymphadenopathy, nausea, diarrhea, rash, and pharyngitis are usually present. Other symptoms include vomiting, arthralgias, and photophobia. Rarely, neurological symptoms and hepatosplenomegaly are seen. Symptoms usually resolve within 15 days.
The rash is characteristically a morbilliform truncal exanthem that may resemble an exanthematous drug eruption or a viral exanthem. The palms and soles are usually spared. An enanthem with erythema and oral ulcers may be seen in more than half of patients with the syndrome. Genital ulcers are seen in around one-third.
PHI is important to recognize from a public health perspective. Patients with PHI are 10 times more likely to transmit HIV compared with patients in the chronic phase of HIV infection. Patients with PHI syndrome are most likely to present to primary care physicians, emergency rooms, urgent care and walk-in centers, or general medicine clinics. Approximately 90% of cases are not diagnosed at the primary encounter.
Related topics: acquired immune deficiency syndrome, HIV/AIDS-related pruritus, HIV-associated lung disease, human immunodeficiency virus disease, papular pruritic eruption of HIV
B20 – Human immunodeficiency virus [HIV] disease
111880001 – Acute HIV infection
Differential Diagnosis & Pitfalls
- Other causes of fever and lymphadenopathy (Epstein-Barr virus infection, cytomegalovirus infection, toxoplasmosis) – Testing for these pathogens can be performed.
- Exanthematous drug eruption if there is a history of preceding medication use.
- Influenza – Lymphadenopathy is not a typical finding and patients have prominent respiratory symptoms.
- Measles – Conjunctivitis, coryza, and cough are usually seen with measles. Patients also have rash and fever.
- Rubella – Rash and lymphadenopathy may be present.
- Secondary syphilis – Patients typically have rash (involvement of the palms and soles is common) and lymphadenopathy.
- Brucellosis – There is a spectrum of possible symptoms. Patients with acute infection are usually febrile and may have lymphadenopathy. The patient should be questioned regarding possible animal exposure or the consumption of unpasteurized dairy products.
- Malaria – Patient should have a consistent travel history.