Introduction:
Adverse drug reactions, which affect 0.1 to 1 percent of individuals using systemic drugs, are a serious health problem. Drugs given to patients systemically can cause drug-induced dermatologic responses, commonly known as toxidermia. People of all ages may be affected. Therefore, the age group that is affected is quite unpredictable. To give patients better care, medical professionals must comprehend the underlying causes of these skin eruptions and the appropriate ways to treat and manage them. The risk factors must be carefully examined, and the dosage must match the patient's circumstances. A crucial part of treatment is stopping the medicine that is causing the reaction.
What Are Unusual Drug-Induced Dermatologic Reactions?
1) Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN):
SJS and TEN are two rare and potentially fatal syndromes. About 70 percent of the time, the eruptions are brought on by drugs. Patients with HIV and lymphoma are most at high risk. Whether it is SJS or TEN depends on the percentage of skin detachment.
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When under ten percent of body surface area (BSA) with skin separation is noted, it is classified as SJS.
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When between 10 and 30 percent of the affected BSA has a lesion, it is characterized as overlapping SJS and TEN.
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If more than 30 percent of BSA is affected, it is categorized as TEN.
Experts believe that specific drugs cause SJS and TEN syndrome. Allopurinol, anticonvulsants, antiretroviral meds, oxicams, and sulfonamides are a few examples of these pharmaceuticals. It is still unclear how the immune system fits into the specific etiology of TEN. Based on the evidence, cytotoxic CD8+ T (cluster of differentiation 8) cells, a particular subset of immune cells, seem to be the main cause of keratinocyte (cells found lower in the epidermis) death and the ensuing skin separation. It is believed that drugs or their metabolites stimulate CD8+ immune cells to an excessive degree. Then, by producing many chemicals, CD8+ T lymphocytes induce keratinocyte cell death.
The symptoms of this drug-induced skin reaction are acute and will appear within 4 weeks of drug exposure. It has also been observed that symptoms can appear days following drug discontinuation. Fever, a sore throat, and stinging eyes are early signs and symptoms. One to two days later, there are mucous erosions and skin blisters, along with significant epidermal separation and sloughing. The lesions begin as erythematous, purpuric macules with an uneven form that gradually merge. The entire body could be covered in rashes. When the causative agent is reintroduced, the eruption happens even faster. At least 85 percent of the patients have problems with their mucous membranes. It is essential to stop using the causative agent. The treatment options include supportive and symptomatic care.
2) Warfarin-Induced Skin Necrosis -
An uncommon side effect of warfarin therapy is warfarin-induced skin necrosis, which can happen to people with a history of thrombophilia or after receiving substantial loading doses of the medication, especially if heparin is not used concurrently at first. Warfarin is a drug used to treat and prevent blood clots. About 1 in 10,000 patients who are exposed to warfarin develop necrosis. Patients who have a genetic deficiency in protein C are more vulnerable because they are more coagulable while starting treatment.
Skin reactions can happen three to five days after starting warfarin. Painful, red plaques start appearing and eventually become ulcers, hemorrhagic blisters, and necrosis. The most commonly affected regions are the breasts, thighs, buttocks, hips, and belly. Blue toe syndrome can also be brought on by early warfarin-induced skin necrosis. The primary goal of treating warfarin-induced skin necrosis is to stop the medication. Heparin can be utilized if anticoagulation is needed. Vitamin K is occasionally used to speed up the effects of warfarin reversal. Protein C concentrates can be utilized if the coagulation is life-threatening.
3) Drug-Induced Lupus (DIL) -
Drug-induced lupus (DIL) is an autoimmune condition in which exposure to drugs causes the development of clinical characteristics similar to those of systemic lupus erythematosus (SLE). Diagnosing drug-induced lupus can be challenging because it can appear weeks to months after beginning the medication. Joint pain is common and usually the initial sign. It is also typical to experience symptoms like myalgia, fever, and weight loss.
Photosensitivity, purpura, erythema nodosum, malar rash, and subacute cutaneous lupus erythematosus (SCLE) rash are among the common cutaneous involvement symptoms. Inflammation can be caused around the lungs or heart, leading to pain or discomfort in DIL. Symptoms usually disappear a few weeks after the condition-causing medication is stopped.
4) Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) -
DRESS syndrome, also known as drug-induced hypersensitivity syndrome, is a severe reaction to certain drugs. It is classified as a type 4 hypersensitivity reaction. There is a ten percent chance of death from this dangerous medication reaction, which affects the skin and other organs. Usually, a high fever is the first to be noted. Immediately after, a broad skin rash appears.
Typical symptoms include measles-like-eruption, which can occur in many other forms, such as pustules, blisters, and targetoid lesions, as well as severe inflammation of the skin and facial edema. Stopping the medicine causing the reaction is the most crucial step in treating DRESS; in some cases, no more care is required. The rash can be treated with topical steroids. Additional treatment is frequently required to prevent harm to the organs.
How Can Drug-Induced Dermatologic Reactions Be Prevented?
A major factor in decreasing the severity and impact of drug-induced skin reactions is prevention. Identifying the patient subgroup most likely to have side effects and adjusting the course of therapy accordingly are fundamental steps in reducing medication responses. Preventive measures can be implemented and enhanced by several means, such as patient education, awareness-raising, surveillance, and data analysis. Through pharmacogenetic testing, all medicines that cause skin eruptions are eliminated. However, it is expensive and is not generally accessible.
What Is the Treatment for Drug-Induced Dermatologic Reactions?
Quitting the medicine causing the drug response is the most efficient strategy to alleviate its effects. Since the medication may take some time to exit the body, discomfort from the hives, skin rash, and other drug response symptoms may last a few days or weeks.
Such discomforts can be managed with medication, including:
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Antihistamines reduce hives and the symptoms of a drug eruption known as morbilliform eruption.
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Corticosteroids lessen inflammation and ease the burning, stinging, swelling, and redness of hives or skin rashes.
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Immunoglobulin administered intravenously will treat Stevens-Johnson syndrome, characterized by extensive skin blistering.
Conclusion:
Some drugs can induce skin reactions in very rare cases. Healthcare professionals should know the characteristics and prevalent causes of acute and long-term drug-induced skin diseases. Suppose a link between the drug and the lesion is discovered. In that case, patients who arrive with a skin rash or other skin lesions should be carefully evaluated, treated if needed, and informed about the drug-induced skin condition. Withdrawal of the drug is the mainstay of treatment, and the patient should be kept under observation.
