Review Question - QID 106443

The subject in the question stem is suffering from Herpes Simplex virus (HSV) infection. Given the location of the lesions, HSV-1 is the most likely culprit.

HSV is a highly-transmissible viral infection of the skin that is characterized by painful, vesicular eruptions on an erythematous base, present at mucocutaneous surfaces. Generally, HSV-1 is responsible for oral-labial disease and HSV-2 is responsible for genital disease. The virus is contracted by direct contact with active lesions and has a relapsing and remitting course. In between flare-ups, the virus lies dormant within the dorsal root ganglion.

Emmert reviews the treatment options for HSV. He reports that while acyclovir remains an effective and inexpensive option, other newer oral antivirals such as famciclovir and valacyclovir might have greater bioavailability and more tolerable dosing regimens. Patients who have six or more recurrences of genital herpes per year can be treated with: acyclovir, 400 mg twice daily; valacyclovir, 1 g daily; or famciclovir, 250 mg twice daily. These regimens are effective in suppressing 70 to 80 percent of symptomatic recurrences. There is little evidence indicating that treatment of recurrent orolabial herpes is beneficial.

Cernik et al. review the clinical approach to treating HSV infections. While the diagnosis is often straightforward, choosing an appropriate drug and dosing regimen might not be as simple in view of (1) competing clinical approaches to therapy; (2) evolving dosing schedules based on new research; (3) approved regimens of the FDA that may not match recommendations of the CDC; and (4) dissimilar regimens for oral and genital infections. The authors report that oral acyclovir suspension (15 mg/kg 5 times daily for 1 week) significantly decreased the disease duration and the period of infectivity in children in a small randomized control trial. For recurrent infections, they report that randomized controlled trials have shown systemic acyclovir (400 mg 5 times daily for 5 days) decreases healing time and viral shedding and ameliorates symptoms when initiated early.

Figure A demonstrates the vesicular perioral lesions characteristics of HSV-1.

Incorrect Answers:
Answers 1 and 2: The vesicular lesions shown in the image are not the result of Staphylococcal infection.
Answer 4: Herpes Simplex virus strain 2 is more commonly seen in genital herpes infections.
Answer 5: Propionibacterium acnes is responsible for acne vulgaris. This is not the classic appearance of acne vulgaris.