Derm Dx: Itchy rash on the groin - Clinical Advisor

Derm Dx: Itchy rash on the groin

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A patient, aged 65 years, presented with complaints of an itchy rash in her groin. The patient had hypertension and hyperlipidemia and was prescribed several medications including atorvastatin and amlodipine.

The patient reported that she was married with three grown children.

Genital herpes has historically been thought to be caused by the HSV-2 virus, although HSV-1 currently causes approximately half of new infections especially in the United States, Canada, and Europe. These viruses are double stranded DNA viruses, and shedding of...

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Genital herpes has historically been thought to be caused by the HSV-2 virus, although HSV-1 currently causes approximately half of new infections especially in the United States, Canada, and Europe.

These viruses are double stranded DNA viruses, and shedding of the virus may occur even in the absence of clinical infection. The virus enters epithelial cells and replicates to form giant cells, then is moved to the nucleus of a sensory dorsal root ganglion where it remains latent until reactivation.

During reactivation, the virus migrates back down the axon to the epithelium. Recurrence occurs when reactivation produces clinical symptoms such as blisters, pain, itch, and ulceration.

Genital herpes infection sometimes presents clinically with a prodromal episode consisting of tingling or itching, which gives way to painful vesicular genital lesions often on an erythematous base.

The key to the diagnosis of herpes is a grouping of vesicles.   If the vesicles fuse together or become eroded, then the borders of the lesion appear scalloped.  The patient may complain of itch instead of pain. 

Subclinical infection may also occur during which lesions are not present but shedding still occurs. Often the patient is asymptomatic during the first episode. Diagnosis is usually made clinically.  PCR has high sensitivity.  Viral culture is a poor test. 

Complications of genital herpes infection include vertical neonatal herpes infection, which may cause potentially fatal disseminated infection in the neonate. Transmission is typically prevented with the use of acyclovir in the peripartum period as well as Caesarian section if an active outbreak is present.

HIV infection is also commonly associated with HSV-2 infection, which increases risk for HIV infection by two to three times, since the open lesions can provide access for the HIV virus to enter the body.

Recurrence is between 20 to 50% for HSV-1 infection and is significantly higher at 70 to 90% for HSV-2 infection. Treatment consists of anti-viral agents such as valacyclovir, famcyclovir, and acyclovir.  

Yasmin Qaseem, BS, is a medical student at Baylor College of Medicine

Adam Rees, MD, a graduate of the David Geffen School of Medicine at UCLA, practices dermatology in Los Angeles.                                                                                            

References

  1. Gupta, R.T et al. The Lancet . 2008; 370 (9605): 2127-2137.
  2. Hofstetter, AM et al. Current Opinion in Infectous Diseases. 2014; 27 (1): 75-83.
  3. Sita A et al. Current Opinion in Virology. 2014; 6: 6-12.
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