Chronic urticaria associated with recurrent genital herpes simplex infection and success of antiviral therapy--a report of two cases.

The role of infectious agents as a cause of chronic idiopathic urticaria (CIU) is uncertain. The objective of this study was to investigate whether genital herpes simplex infection is causally related to CIU. We identified two patients with recurrent genital herpes simplex infections associated with CIU. Episodes of genital herpes were especially associated with acute exacerbation of urticaria. Anti-herpes simplex 2 antibodies and Tzanck smears were done in both patients, along with other relevant investigations for CIU. Acyclovir was added to antihistamine therapy. Both patients were apparently in good health and appeared clinically immunologically stable, though one of them was found to be diabetic. Clinical and laboratory investigations for genital lesions supported a diagnosis of herpes simplex. Anti-herpes simplex 2 antibodies were markedly raised in both patients. The Tzanck smear was positive in one case and negative in the other, despite a definitive clinical diagnosis of herpes progenitalis. CIU, which was inadequately controlled with antihistamines alone, responded dramatically to the addition of acyclovir therapy. Our results may not be applicable to other patients with CIU, especially when there is inadequate evidence of an association with genital herpes. CIU may be associated with recurrent genital herpes simplex infection. In such situations, the addition of acyclovir to therapy may be beneficial.