Herpes Simplex Virus Infection (HSV)

Neuraxial morphine can reactivate it - Neuraxial administration of morphine has been reported to reactivate herpes simplex, classically as orolabial lesions a few days after cesarean delivery. It is not a reason to withhold good analgesia, but it is worth mentioning at consent so a cold sore on postoperative day two is not read as a complication of the block.

Primary infection is not the same as recurrent - Women who acquire genital HSV during pregnancy carry a considerably higher risk of transmitting it to the neonate than women with recurrent disease, and primary infection brings systemic symptoms — fever, headache, malaise. Sort out which one you are dealing with from the history and the obstetric record before you plan the anesthetic. Inspect the intended puncture site yourself; never put a needle through a lesion.

Herpetic whitlow is an occupational hazard - In adults, medical and dental work is a named risk factor for herpetic whitlow, and in adults it is most often HSV-2. It comes from bare-handed contact with oral or genital secretions — which is a description of airway management. Glove for every airway manipulation and oral exam, and change gloves between cases rather than carrying a pair forward.

Painful oral lesions change the airway plan - Primary herpetic gingivostomatitis produces high fever with painful ulcerative lesions across the gingiva, palate, and buccal and labial mucosa. Those ulcers bleed readily and take two to three weeks to heal, so look in the mouth before choosing a technique. Poor oral intake from the pain means these patients often arrive dehydrated.

Immunosuppression turns it severe - Transplant recipients and patients with HIV, leukemia, or lymphoma get severe, chronic, or disseminated HSV rather than a cold sore. Acyclovir resistance is uncommon in immunocompetent patients (under 1%) but common enough after hematopoietic stem cell transplant to change the treatment conversation.

Eczema herpeticum is an emergency - Disseminated cutaneous HSV on a broken skin barrier — atopic dermatitis, ichthyosis, Darier disease, or topical calcineurin inhibitor use — is rare but rapidly progressive and potentially fatal. Extensive involvement, systemic symptoms, or reduced oral intake buys admission and IV acyclovir. Site lines, monitors, and adhesive on intact skin.

CNS, visceral, or disseminated disease goes intravenous - Limited mucocutaneous lesions can be treated orally, but CNS, visceral, or disseminated involvement requires IV acyclovir. Acyclovir is first-line for HSV encephalitis and nothing else is indicated for it.

IV acyclovir is nephrotoxic - Acute kidney injury from acyclovir crystal deposition in the renal tubules is the most significant adverse effect of the parenteral drug, at an incidence comparable to aminoglycosides. Infuse over a full hour at a constant rate, diluted to 7 mg/mL or less, and keep the patient hydrated intraoperatively. Risk climbs with obesity, concurrent vancomycin, higher baseline creatinine, higher dose, and longer duration.

Acyclovir neurotoxicity looks like delirium - Agitation, confusion, altered consciousness, and hallucinations appear on average about three days into therapy, overwhelmingly in patients with renal impairment who were dosed above guideline for their clearance. A confused postoperative patient on IV acyclovir with a rising creatinine has a drug problem, not a delirium problem — check the dose against the creatinine clearance.

Ocular disease - Herpes simplex keratitis can progress to corneal perforation or blindness, and ocular HSV is a common cause of blindness in the United States. Tape the eyes early and keep anything off the cornea in a patient with known ocular involvement.

Keep the antiviral going in transplant patients - Prophylactic acyclovir is recommended in HSV-1 and HSV-2 seropositive organ recipients and reduces reactivation after hematopoietic stem cell transplant; reactivation is common once prophylaxis stops. Confirm the antiviral is on the medication list and continued perioperatively rather than held along with everything else.

Herpes simplex virus (HSV) is a double-stranded DNA alphaherpesvirus. HSV-1 spreads through saliva and causes most orolabial disease; HSV-2 spreads sexually and causes most genital disease, with seropositivity around 22% of US adults aged 12 and older. Both follow the same cycle: replication in mucocutaneous epithelium, retrograde axonal travel to the trigeminal, cervical, lumbosacral, or autonomic ganglia, lifelong latency there, then reactivation back down that sensory nerve to produce vesicles in its dermatome.

Reactivation is what makes HSV our problem. Most of it is asymptomatic shedding, but it is triggered by stress, immunosuppression, and — directly relevant to anesthesia — neuraxial morphine. In an immunocompromised host the same virus produces severe, chronic, or disseminated disease, and HSV encephalitis is the leading cause of lethal encephalitis in the United States.