Erythema multiforme is an acute and self-limiting mucocutaneous hypersensitivity reaction
triggered by certain infections and medications. One of the most common predisposing factors for erythema multiforme is infection with herpes simplex virus (HSV). HAEM is an acute exudative dermatic and mucosal disease caused by the infecting HSV. It has a recurrence and idiorestriction, characterised by increasing of CD4+ T leucomonocytes.
Drugs, including dioclofenac sodium, sulfonamides and penicillins, also predispose to thedevelopment of erythema multiforme. Alpinia galanga is a known Siddha drug used by thattraditional medicinal system for treating numerous acute and chronic inflammatory disorder. The anti-inflammatory action of Alpinia galanga is due to active phytochemical components such as 10-acetoxychavicol acetate (ACA) and trans-p-hydroxycinnamaldehyde present in it.
The most common trigger for the development of EM is the HSV (HSV-1 and HSV-2). The pathogenesis of HAEM is consistent with a delayed hypersensitivity reaction. The disease begins with the transport of HSV DNA fragments by circulating peripheral blood mononuclear CD34+ cells (Langerhans cell precursors) to keratinocytes, which leads to the recruitment of HSV-specific CD4+ Th1 cells. The inflammatory cascade is initiated by interferon γ (IFN-γ), which is released from the CD4+ cells in response to viral antigens, and immunomediated epidermal damage subsequently begins.
Treatment of erythema multiforme depends on the severity of the clinical features. Mild forms usually heal in 2–6 weeks; local wound care, topical analgesics or anaesthetics for pain control,
and a liquid diet, are often indicated in these situations. For more severe cases, intensive management with intravenous fluid therapy may be necessary. Oral antihistamines and topical steroids may also be necessary to provide symptom relief. Systemic corticosteroids have been used successfully in some patients, but evidence to support their use for erythema multiforme is limited.
In case of HAEM, it is effectively managed with acyclovir (200 mg, 5 times a day for 5 days), but only if the therapeutic scheme is started in the first few days. If erythema multiforme keeps recurring, a continuous low dose of oral acyclovir is necessary. Oral acyclovir has been shown to be effective at preventing recurrent HAEM and the protocols may include 200–800 mg/day for 26 weeks.