Definition

Erythema multiforme is a hypersensitivity reaction characterized by skin redness or a rash that resembles a circular target. This condition is characterized by the presence of skin redness in different shapes. The term "erythema" is derived from Latin and refers to redness, while "multiforme" denotes multiple shapes. The predominant manifestation of this illness typically presents as a circular rash with a centrally located dark region, like the pattern of a 'target' board.

This rash may manifest after:

• Experiencing specific infections, such as herpes simplex infections, Mycoplasma pneumoniae bacterial infections, and other types of infections
• Taking certain antibiotics such as penicillin, cephalosporin, or anti-tuberculosis medications
• Contact with herbal agents
• Coming into contact with metal
• Vaccination

Erythema multiforme can manifest at many stages of life. However, it is more prevalent among young adults. The average age of those diagnosed with this condition is between 20 and 30 years, with around 20 percent of cases affecting minors. Erythema multiforme is more prevalent in men, occurring at a ratio of 5:1 compared to women. The prevalence of erythema multiforme is rather low, affecting around 1% of the global population.

Erythema multiforme presents in two types, namely:

Erythema Multiforme Minor

This condition manifests as mild red rashes on the skin. The symptoms consist solely of erythematous skin lesions accompanied by itching and do not affect the mucous membranes (such as canker sores or vision abnormalities).

Erythema Multiforme Major 

This is a medical condition characterized by red skin rashes that also affect the mucous membranes. This condition poses a greater risk and has the potential to be life-threatening.

Causes

The etiology of erythema multiforme remains unclear; however, several cases suggest that the condition often manifests after drug usage or infection with specific pathogens. Erythema multiforme is non-communicable, meaning it cannot be spread from person to person. The etiology of erythema multiforme encompasses the following factors:

Infection

A viral infection, such as the herpes simplex virus, is a common cause of infection. Following infection, this virus can persist or remain dormant within the body and can reactivate after a span of several years. The first signs are the appearance of canker sores around the lips, which are then followed by symptoms of erythema multiforme within a few days. Erythema multiforme can also be induced by Mycoplasma sp. bacterium infection, which is capable of causing lung infections.

Medicines

Certain medicines have the potential to induce severe erythema multiforme. Medications that frequently cause this response include:

• Antibiotics, such as tetracycline, amoxicillin, and ampicillin
• Analgesics or painkillers, such as ibuprofen
• Anticonvulsants, such as phenytoin and barbiturates

Vaccine

Multiple case reports document the incidence of erythema multiforme following vaccines with MMR, smallpox, varicella, influenza, and DPT. Nevertheless, the rate of occurrence of this event is small.

Risk factor

Potential risk factors for developing erythema multiforme include:

• Male young adults in the age range of 20 to 30 years old
• Individuals with specific immune system problems, such as:
• HIV or autoimmune disorders
• They are using immunosuppressive medications such as corticosteroids that weaken their immune system
• Spinal cord transplantation
• Malignancy or cancer, such as leukemia or lymphoma.

Symptoms

Onset of skin rashes or erythema may manifest within a few days following exposure or infection. This skin rash, resembling targets, initially manifests on the feet or hands and later extends to the arms, body, and face. The symptoms of redness caused by erythema multiforme exhibit distinct characteristics, including:

• The rashes initially manifest as small red dots that subsequently emerge and increase in size, measuring in the centimeter range
• The reddish lesions resemble targets, with a darker area in the central section, occasionally appearing dark red or accompanied by yellowish crusts, surrounded by paler outer lesions
• Induces pruritus or discomfort
• The lesions vanish after 2 to 4 weeks
• In more severe circumstances, the red lesions could merge together, creating a single large, red, and agonizing lesion

Other symptoms that might occur in this condition include:

• Elevated body temperature 
• Headache
• Canker sores that cause pain and hinder eating or drinking 
• Swollen lips with crusts forming around them
• Genital discomfort accompanied by dysuria
• Red eyes with pain
• Sensitive to light
• Blurred vision
• Joint pain

Diagnosis

A doctor establishes the diagnosis by evaluating the symptoms described by the patient and conducting a thorough physical examination of the skin, mouth, eyes, lungs, and genitals. A diagnosis of erythema multiforme can be made by observing the pattern of skin lesions. If there is uncertainty, other diagnostic tests could be requested, such as:

• Blood tests
• Liver function tests
• Markers of inflammation
• Serological testing for certain infections
• X-ray imaging
• Skin biopsy is a procedure that involves the collection of a sample of skin tissue to be analyzed under a microscope

It is recommended that all individuals displaying signs of erythema multiforme should undergo a herpes simplex examination, which involves collecting samples from the skin or mucous membranes. If erythema multiforme persists or fails to resolve, the doctor could request further tests to identify any potential underlying conditions that may be causing the symptoms.

Management

Prior to carrying out further tests, the fundamental cause of erythema multiforme should be sought. In addition, the doctor will prescribe medication aimed at alleviating symptoms and halting the progression of skin inflammation and infection. The doctor will perform the following actions:

• Cease the use of suspected medication as the cause of erythema multiforme in patients. Discontinuing treatment should not be done without prior consultation with a medical professional.
• Prescribe oral medication and moisturizing cream to alleviate itchy symptoms.
• Give topical corticosteroid for alleviating skin redness and inflammation
• Analgesics to relieve pain in the skin.
• If the doctor feels that your erythema multiforme was caused by a viral infection, they can prescribe antiviral medicine for you.
• Mouthwash can be used to alleviate pain and discomfort in the mouth caused by canker sores. 

For more severe cases of erythema multiforme, the doctor will recommend hospitalization and close monitoring of the patient. Throughout the course of treatment, the physician will offer:

• Stronger analgesics
• Fluid therapy
• Proper wound care to decrease the risk of skin infections
• Convert solid food to a liquid form if required
• Administering corticosteroids to mitigate inflammation
• Treatment for ocular inflammation 

Complications

The majority of individuals diagnosed with erythema multiforme experience a full recovery within a span of a few weeks. Typically, there are no additional issues, and the skin can recover without any scarring.

Erythema multiforme can reoccur in the future, particularly if it is caused by herpes simplex virus infection. In addition, when erythema multiforme reaches a severe stage, it can lead to several problems including:

• Sepsis is a severe condition characterized by the invasion of bacteria into the bloodstream, resulting in multi-organ dysfunctions
• Cellulitis is a dermatological illness characterized by erythema, edema, and discomfort in the affected skin areas
• Scars and permanent skin damage
• Permanent eye disorders
• Persistent inflammation of many organs that can impair the functioning of these organs, including the liver and lungs 

Prevention

Prevention of erythema multiforme is not possible. To prevent the recurrence of this condition caused by herpes simplex, it is necessary to cure the herpes infection fully. Once the doctor has identified the specific triggers for your disease, it is advisable to steer clear of any contact with the materials or substances that could provoke your allergic reaction in the future.

When to see a doctor?

Promptly seek medical attention if you or someone nearby develops persistent symptoms of skin rashes, particularly if you experience fever, headache, swelling, or problems with your eyes. Prior to providing further treatment, the physician will examine you to verify your condition.

Looking for more information about other diseases? Click here!