2025 – PAGE 313 – INFECTIOUS DISEASES
EPSTEIN-BARR VIRUS (EBV)
Epstein-Barr virus (EBV) causes INFECTIOUS MONONUCLEOSIS. Look for fever, sore throat (often an exudative pharyngitis), very prominent and multifocal lymphadenopathy, malaise, URI symptoms, and atypical lymphocytes. The fever can be high and long-lasting (1–2 weeks). Mono can even present with hepatomegaly and mild RUQ TTP. Diagnosis is made with EBV IgM titers even if the monospot SCREEN is negative.
PEARL: Look at the entire clinical picture very carefully when dealing with a case of mononucleosis versus Strep. The monospot SCREEN can be POSITIVE for months after an asymptomatic mono infection. Also, both a Strep SCREEN and a Strep CULTURE will be positive in CARRIERS.
PEARL: Differential diagnosis of atypical lymphocytes includes leukemia! Also, palatal petechiae MAY be present in both Strep and mono patients (more common with Strep).
HUMAN HERPES VIRUS 6 (AKA HHV-6)
Human herpes virus 6 (AKA HHV-6) causes ROSEOLA. Look for a child 6 months to 2 years of age with sudden onset of HIGH fever. The patient may also have neurological symptoms including SEIZURE or encephalopathy. The KEY is to look for a RASH A FEW DAYS AFTER THE FEVER SUBSIDES. The rash is usually on the neck, trunk, and thighs. Children may return to school after the fever is gone, even if the rash is present!
MNEMONIC: Look for an infant or toddler who feels and looks like a ½ DOZEN (6) ROSY ROSES. Well, of course she does now that the FEVER’S GONE and the patient finally presents to the doc!
IMAGE: www.pbrlinks.com/HHV1
(DOUBLE TAKE) HERPES SIMPLEX VIRUS (HSV)
- HERPES SIMPLEXVIRUS (HSV) AS AN STD: The initial flare is often very painful. Pain may precede the presentation of lesions. Look for multiple, painful ulcers or vesicles on the labia or penis. The patient can have lymphadenopathy. The vesicles are CLUSTERED on an ERYTHEMATOUS BASE. Lesions can also be ULCERATIVE. Diagnose by obtaining HSV PCR or a viral culture. The Tzanck smear is not specific for HSV. Treat with ORAL (not topical) Acyclovir x 7 days. Treat babies with IV Acyclovir. Note that valacyclovir and famciclovir are also similarly efficacious, but they tend to be more expensive.
- IMAGE: www.pbrlinks.com/HSV1
- PEARL: HSV can be associated with a very painful infection called a HERPETIC WHITLOW (typically of a thumb or finger).
- IMAGE: www.pbrlinks.com/HSV2
- HERPES SIMPLEX VIRUS ENCEPHALITIS(HSV ENCEPHALITIS): Look for fever, seizures and mentioning of the temporal lobe on CT brain. Treatment is STAT IV acyclovir, followed by a lumbar puncture to obtain fluid for PCR testing. An EEG might show PLEDs (periodic lateralizing epileptiform discharges).
- (DOUBLE TAKE) HERPES SIMPLEX VIRUS GINGIVOSTOMATITIS: Herpes simplex virus gingivostomatitispresents with oral and perioral/vermillion border lesions/vesicles. Gingiva is friable and malodorous. There is associated lymphadenopathy. Usually caused by HSV-1. Can treat with oral acyclovir. Treat immunocompromised hosts with IV acyclovir.