Herpes Simplex Virus: New Testing, New Thinking.

Abstract

A normally healthy, thriving, fully immunized 14-month-old twin girl with no history of eczema or other medical problems presented with a 2-cm raised erythematous nonpurulent lesion on her right shoulder, associated with a fever to 38.3°C. She was prescribed amoxicillin for a presumed bacterial skin/soft tissue infection (SSTI). The fever resolved after 24 hours, and our patient completed a 10-day course of amoxicillin. Her mother noted initial improvement, but then recurrence of the lesion with the development of coalescing vesicles with clear drainage on the erythematous base. SSTIs can develop after there is a break in the integrity of the skin. They are frequently caused by bacteria, with the 2 most common agents being Staphylococcus aureus and group A Streptococcus . These infections can manifest as a superficial folliculitis; impetigo, which may have vesicles, crusting, or bullae; or a deeper cellulitis or abscess formation. Fungal infections caused by dermatophytes usually present as focal round skin lesions with scaling but can occasionally have vesicles. Scabies, a reaction to a mite infestation, would also be in the differential for a child presenting with multiple papular lesions and pruritus. Finally, viruses including herpes simplex virus (HSV) types 1 and 2 (HSV-1 and HSV-2), and varicella zoster virus (VZV) may also present with vesicular skin lesions. In a study published in 2013, 7585 children vaccinated against varicella between 1995 and 2009 were followed to document breakthrough varicella and herpes zoster infections. Over the 14 years of the study, 1505 breakthrough cases of varicella were reported (≥6 weeks after initial vaccination). All cases were after the first dose. Seventy-four percent of patients had mild illness with <50 total lesions.1 HSV (types 1 and 2) is a DNA virus that commonly causes illness in humans. HSV is spread by direct contact with an infected lesion …