A drug eruption is an adverse reaction to a medication. There are various types of drug eruptions that range in severity with some that is so mild that can go unnoticed or can create a life-threatening condition. The common drug eruptions include the morbilliform drug eruption and urticarial or angioedema. Depending on the cases, re-exposure to the medication is possible as the sensitivity may be lost over the period of time or that the underlying illness that caused the adverse reaction may be resolved. It is estimated that around 2% of new medications can result in drug eruption.
Causes
Females more commonly develop allergic reactions to certain medications that the male population. The drug eruption can also be caused by the previous allergic drug reaction that can increase the risk of another reaction to medications, drug intolerance and an underlying infections or illness. Other causes of drug eruptions can include true allergy that occurs due to the immunological mechanism where the reaction can either occur immediately after exposure to the drug within an hour or can be delayed for 6 hours.
Symptoms
Some of the drugs associated rashes include
- Acneform lesions that may appear over the upper body
- Acute generalized exanthematous pustulosis that presents superficial pustules
- Hypersensitivity vasculitis is the condition of the inflamed blood vessels
- Drug fixed eruptions; an allergic reaction to medication that typically recurs in the same location each time the medication is taken
- Lichenoid drug eruption which is the uncommon skin rashes
- Drug-induced photosensitivity can develop as blistering rash on the sun-exposed areas of the skin such as the face, neck, arms, lower legs and feet
- Drug-induced lupus erythematosus that causes lupus-like syndrome as a reaction to certain medications but may resolve once the medication is ceased
- Certain medications can also cause hair loss, nail dystrophy, allergic contact dermatitis, photocontact dermatitis and skin pigmentation
- The clinical features of drug eruptions include fever, malaise and organ involvement such as the kidney and the liver.
Diagnosis
The diagnosis is based on the evaluation of the individual’s history, physical examination and the skin observation. It is also important to assess the individual’s previous exposure to certain medication and depending on the case, the medication may be stopped and reintroduced later to determine if the symptoms persist. Additional tests can include blood count, kidney function test and to evaluate the function of the liver as well. A patch test may be used with medication that is suspected to cause the symptoms.
Treatment
The treatment is mainly focused on stopping the medication that is responsible for cause this condition. To relieve the symptoms, various treatments can include topical corticosteroids and antihistamines. It is important that the individuals remember the type of medication that causes the adverse reaction to avoid re-exposure in the future.
References
http://www.dermnetnz.org/topics/drug-eruptions/
http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/dermatology/drug-eruptions/#top