Like other allergies, the delayed type of drug sensitivity can include antibody-dependent cytotoxicity, such as antibody-dependent thrombocytopenia, or the formation of an immune complex, such as serum sickness-like syndrome, which is an example of the use of antibiotics and the type dependent on cellular immunity. We are now going to present an article about this type , which is also known as delayed hypersensitivity
. It involves only the skin or is accompanied by systemic and visceral involvement, and the other type is divided into severe or non-severe, which mildly involves only the skin (itching of the skin is often seen in all types, in case of first exposure, you should think about delayed reaction Let’s take medicine and if it gets worse and faster, we should ask about this deterioration and if it is severe, we should admit him to a well-equipped hospital and not only identify the drug or drugs that are the culprit, but also immediately stop taking similar drugs, and this prohibition should be with the patient for the rest of his life. It is necessary to suggest an alternative drug and report this reaction to the authorities, and allergists should be their future advice on the path of their drug life and define a kind of drug passport for patients, and in most cases, the culprit of these drugs is their first use. The only local type is maculo-papular lesions on the skin, which fortunately is 90% delayed drug reactions and occurs between 4 and 21 days after the start of use, although the lesions are seen in less than 2 days after repeated use (the date of end of use does not play a role in defining the delayed type) The lesions are similar to measles (morbilliform) with a good general condition, it starts from the trunk and resolves with pressure (rarely it becomes purpuric on the legs and it is still present with pressure) and if the lesion is a target, the skin inside is healthy, mucosa involvement (mouth eyes and nose) and it gets better within 2 weeks without any treatment, which is accompanied by crusting, drugs such as aminopenicillins, sulfonamides, carbamazepine, allopurinol, and non-steroidal analgesics play a role in causing it. Other types, only localized, chronic, delayed urticaria, lichenoid, eczematoid lesions and a fixed drug reaction, which always causes the same lesion in the same place, severity and extent when taking the drug . It is a severe type, but it has a good course. Severe or systemic types are usually fatal and require hospitalization and are fortunately rare
Erythema multiformal
- is evident from its name, that the skin lesions have different shapes, sizes, and even volumes, and it is mostly due to herpes infections (cold sores) and chlamydia pneumonia, and only 20% of its cases are caused by the use of barbiturates (phenobarb, etc.), ciprofloxacin, and other analgesics. Steroids and even aminopenicillins may involve the mucous membrane (mouth) but without ulceration.
- Steven Johnson syndrome and toxic epidermal necroses
are degrees of a disease that is the most fatal type (30% fatal) Erythema multiforme with fever, malaise, and eye and face tightness at the beginning, skin lesions first appear similar macules on the trunk and then worse The targets become a prominent wound inside, mainly vesicles and blisters, and the mucous membrane of the eyes, mouth, and genitals is caught. During the examination (even), the epidermis of the skin is separated from the underlying surface (Nikolsky’s signs)
. Up to 10% of the skin surface involvement is Johnson’s acetone, and above 30% it becomes epidermolitoxic, and it is called an overlap between the two,
and if it reaches 90%, it is called exfoliative dermatitis. - The acute general pustular reaction
appears with redness and burning patches on the face, armpits, and groin, and the fever is severe, and a large number of purulent pimples appear quickly. The fastest drug reaction is delayed, and it starts less than two days, even less than one day, and it gets better within 2 weeks, and 80% of cases are caused by the use of antibiotics, and if we make a mistake for antibiotic treatment, the patient gets worse. - Drug-induced hypersensitivity,
drug reaction and eosinophilia with systemic symptoms is another name for it, with fever, lethargy, joint pain, enlarged lymph nodes, hepatosplenomegaly, and even involvement of the lungs and kidneys, and in the blood, an increase in eosinophils and lymphocytes (even atypical) and an increase in markers Inflammation… the onset and skin lesions range from mild maculopapular to widespread involvement of the entire skin with high severity. It is the most delayed drug reaction and can be seen 2 to 8 weeks after taking it. It is very long and persistent. It has phases of recovery and relapse, and during the course of the disease, it also awakens latent viruses, which increases the severity of the disease. It mostly occurs in elderly people over 60 years old, and anticonvulsant drugs such as carbamazepine are the cause. - Medicinal vasculitis
is the creation of auto-immunity with drugs, which in the skin causes purpura and lupus-like lesions along with arthritis and muscle inflammation or kidney and lung involvement, and in the blood, an increase in ANA and anticardiolipin NK, an increase in immunoglobulin M, and a decrease in complement C4, distinguishing medicinal vasculitis from the idiopathic type, these abnormal tests in It is a drug model and the most important drug that causes vasculitis is anti-thyroid drugs, and it occurs even months after the start of anti-thyroid drugs.
Kidney or liver involvement has been separately reported as a drug reaction up to 3 months after the start of use.
Clinical exposure
If a drug has been discontinued and 5 times its half-life has passed and no reaction has occurred, then that drug is no longer considered to be accused for skin lesions that started more than a few days ago or is very improbable.
If the history of previous use and the same lesions have been repeated, it is certain that the drug is the culprit, although most of the cases are in the first place, and usually no one uses it anymore. is).
The first step is
to stop the drug. It is very important to stop the culprit drug as soon as possible. It is the first step. However, we must be careful not to blame all the drugs and not to stop taking the drug that is not blamed so that the underlying problem does not become a problem.
Exceptions:
Although the culprit drug has been identified, due to the mildness of the lesions or due to the importance of the underlying disease, sometimes we continue to use the culprit drug, which we have to do in the hospital, such as the treatment of nemocystic carinitis in AIDS with sulfonamide.