Fixed Drug Eruption

Key Points
Skin condition caused by a reaction to medication
Most commonly presents as an itchy reddish, brown patch of skin “fixed” to a given area and recurring in the same location with each subsequent medication exposure

A Fixed drug eruption is a skin condition caused by a reaction to medication. The most common symptom, which occurs in most cases, is itching. The term fixed drug eruption describes the development of one or more round or oval red patches as a result of systemic exposure to a drug. These reactions normally resolve with brownish staining of the skin (Hyperpigmentation) and may recur at the same site with reexposure to the drug.

Fixed drug eruptions can affect any age, race, or gender. Persons with weakened immune systems, underlying infection, or those who take multiple medications daily are at a greater risk of developing the condition. Any medication may cause an eruption, but certain medications are more likely to do so. These medications include Antibiotics, anti-inflammatories, certain painkillers, anti-convulsants, chemotherapy drugs, psychotropics, diuretics, and iodine.

Differential Diagnosis (Other conditions with similar appearance)

Acute Febrile Neutrophilic Dermatosis
Measles
Contact Dermatitis
Pityriasis rosea
Erythema
Psoriasis
Rubella
Erythroderma
Syphilis
Urticaria
Hypersensitivity Vasculitis
Lichen Planus

Diagnosis
Key Points
Diagnosis based on appearance of symptoms in conjunction with taking a new medication
Skin biopsy and/or blood tests may be performed to determine if allergies exist and to rule out other similar-appearing conditions

Initial diagnosis is based on the appearance of symptoms in conjunction with the administration of a new medication. Health care professionals will then perform biopsies of the affect area or blood tests to determine if allergies exists, to what drug the reaction is attributable, and to rule out other, similar appearing conditions.

Treatment
Severe cases with widespread coverage should be treated by health care professionals or emergency medical care
For mild cases, several self care treatments may help in alleviating symptoms
Once determined, the causal medication should cease to be administered
Symptoms may take up to 3 weeks to disappear completely
OTC Options: Cortisone creams, oral Antihistamines, calamine lotion

Fixed drug eruptions are best treated by stopping administration of the causal medication. In the case of mild reactions, administration of oral antihistamines, a cool shower or application of cool compresses to the affected area, and the use of calamine lotion can relieve symptoms.

It is recommended that health care professionals or emergency medical care be sought immediately in the case of severe reactions. Once diagnosis is established, doctors may use cortisone creams and antihistamines to treat symptoms. It may take 5-10 days to see an improvement of symptoms, and up to 3 weeks for them to disappear completely.