ESSENTIALS OF DIAGNOSIS
Recurrent small, grouped vesicles (especially orolabial and genital) on an erythematous base.
May follow minor infections, trauma, stress, or sun exposure.
Regional tender lymphadenopathy may occur.
Direct fluorescent antibody or PCR tests are positive.
Over 85% of adults have serologic evidence of herpes simplex type 1 (HSV-1) infections, most often acquired asymptomatically in childhood. Occasionally, primary infections may be manifested as severe gingivostomatitis. Thereafter, the patient may have recurrent self-limited attacks, provoked by sun exposure, orofacial surgery, fever, viral infection, or immunosuppression.
About 25% of the US population has serologic evidence of infection with herpes simplex type 2 (HSV-2). HSV-2 causes lesions whose morphology and natural history are similar to those caused by HSV-1 but are typically located on the genitalia or buttocks of both sexes. The infection is acquired by sexual contact. In monogamous heterosexual couples where one partner has HSV-2 infection, seroconversion of the noninfected partner occurs in 10% over a 1-year period. Up to 70% of such infections appeared to be transmitted during periods of asymptomatic shedding. Genital herpes may also be due to HSV-1.
The principal symptoms are burning and stinging. Neuralgia may precede or accompany attacks. The lesions consist of small, grouped vesicles on an erythematous base that can occur anywhere but that most often occur on the vermilion border of the lips (eFigure 6–40) (eFigure 6–41) (Figure 6–12), the oral cavity (eFigure 6–42), penile shaft, the labia, the perianal skin, and the buttocks. Any erosion or fissure in the anogenital region can be due to herpes simplex. Regional lymph nodes may be swollen and tender. The lesions usually crust and heal in 1 week. Immunosuppressed patients may have unusual variants, including verrucous or nodular herpes lesions at typical sites of involvement. Lesions of herpes simplex must be distinguished from chancroid, syphilis, lymphogranuloma venereum, pyoderma gangrenosum, or trauma.
Herpes simplex. (Used, with permission, from TG Berger, MD, Dept. Dermatology, UCSF.)
Close-up of recurrent herpes simplex virus-1 showing vesicles at the vermilion border. (Reproduced, with permission, from Richard P. Usatine, MD, in Usatine RP, Smith MA, Mayeaux EJ Jr, Chumley HS. The Color Atlas and Synopsis of Family Medicine, 3rd ed. McGraw-Hill, 2019.)
Orolabial herpes simplex showing deroofed blisters (ulcer). (Reproduced with permission from Richard P. Usatine, MD, in Usatine RP, Smith MA, Mayeaux EJ Jr, Chumley H. The Color Atlas of Family Medicine, 2nd ed. McGraw-Hill, 2013.)
Primary herpetic stomatitis...