Dermatology - Erythema Multiforme Syndrome

Dermatology - Erythema Multiforme Syndrome
Erythema multiforme is a frequent reaction pattern of blood vessels in the dermis with secondary epidermal changes that appear as erythematous iris-shaped papular and vesiculobullous lesions on the extremities (particularly the palms and soles) and the mucous membranes. Erythema multiforme minor is a dermatological response triggered by the presence of herpes simplex virus. The age at which erythema multiforme often begins is typically under 20 years old. Additionally, this condition is more commonly observed in males and boys compared to females and girls.

The course of the disease is typically benign, but recurrences are common until effectively controlled by long-term therapy specifically targeting the herpes simplex virus, if it is the underlying cause. The lesions progress gradually over a span of several days and might cause itching or pain, especially in the mouth. Severe manifestations of the condition include constitutional symptoms such as fever, weakness, and malaise. Recurrences are typically linked to a herpes simplex outbreak that occurs few days prior. Severe outbreaks of EM major primarily manifest as medication responses and consistently involve the mucous membranes. These outbreaks are characterized by their severity, widespread nature, tendency to merge together, and formation of blisters. Additionally, erythematous lesions in these outbreaks exhibit a positive Nikolsky sign. 

Systemic symptoms include fever and prostration. Cheilitis and stomatitis disrupt the process of eating, whereas vulvitis and balanitis interfere with the process of urination. Conjunctivitis can result in the development of keratitis and ulceration, as well as lesions in the pharynx and larynx.
Abnormalities
The formation of lesions typically takes around 10 days, sometimes longer. Initially, they appear as flat spots known as macules, which then progress into raised bumps measuring 1 to 2 centimeters in diameter. These bumps eventually grow fluid-filled sacs called vesicles and larger fluid-filled sacs called bullae in their core. Characteristic iris or targetoid lesions manifest as a dull red color. The lesions might be limited to the hands and face or spread throughout the body, and they are frequently symmetrical and present on both sides. Lesions are also present on the forearms, elbows, knees, and genitalia. The oral cavity may exhibit erosions characterized by fibrin membranes, and in some cases, ulcerations

The diagnosis is made by a clinical approach that relies on the patient's medical history and physical examination. The differential diagnosis comprises drug eruption, psoriasis, secondary syphilis, urticaria, and widespread Sweet syndrome.
Lesions of the mucous membrane can be challenging to diagnose due to the potential presence of many conditions such as bullous illnesses, fixed drug eruption, acute lupus erythematosus, and primary herpetic gingivostomatitis.

Administration of oral valacyclovir or famciclovir can potentially hinder the occurrence of recurrent erythema multiforme. Administer systemic glucocorticoids (such as prednisone) to extremely unwell patients at a dosage of 50-80 mg per day, divided into multiple doses, and gradually reduce the dosage.