Drug-inducedAdverse reactionsIt is very complicated and can be roughly divided into: drug overdose, intolerance, idiopathic, side effects,Secondary effectandAnaphylactic reactionEtc.Drug eruption is the most common type of allergic reaction.
Foreign name
drugeruption
Alias
Drug induced dermatitis
Visiting department
the skin department
Common causes
Antipyretic and analgesic drugs, sulfonamides, sleeping and sedative drugs, antibiotics, Chinese herbal medicine
Penicillin is the most common, and others arefuran 、PhenothiazinesIt is not uncommon for drug eruptions to occur.
5. Chinese herbal medicine
In recent years, the reports of drug eruptions caused by Chinese herbal medicines have gradually increased, and the drugs that cause allergies include single Chinese herbal medicines, as well asCompound preparation。
clinical manifestation
Announce
edit
Generally speaking, drug eruptions usually occur after sensitization 7 to 10 days after the start of treatment.However, if you have received the same drug or drug treatment of the same structure before, it can appear quickly within a few hours or 1~2 days.The common skin manifestations of drug eruption mainly include the following types.
1. Eruptive drug eruption
It is the most common type of drug eruption, accounting for 95% of all drug eruptions.The clinical manifestations areDiffuseBright red spots or half rice grains to beansred maculopapules , denseSymmetrical distribution, in the form ofmeaslesSample orScarlatinaLike, sudden onset, often accompanied byChilliness、High fever（39～40℃）headache, general discomfort, etc., more than half of the cases completely subsided 2 weeks after drug withdrawal.If the drug is not stopped in time, it may develop into exfoliationdermatitis, thenPoor prognosis。
It is one of the common drug eruptionsPathogenesisIt can be IType III allergy。rashIt is characterized by unequal sizeWheal, this kind of wheal rash is more commonUrticariaIt is bright red and lasts for a long time. It is itchy and can be accompanied by tingling and tenderness.UrticariaIt can appear as the only symptom, or serum sickness like syndromeAnaphylactic shockA symptom of.In general, allergic patients began to develop wheal rash and pruritus several hours after drug administration, but a few patients were injecting penicillinserum albuminIt will appear within a few minutes after the drugdizzy, upset, extensive red wind mass, itching and decreased blood pressure.
It is often due to failure to stop sensitizing drugs and proper treatment for general drug eruption patients in time, resulting in the development of the disease and the fusion of the rash, which becomes exfoliativedermatitis, or the disease starts suddenly.Skin lesionIt is characterized by bright red and swollen skin, accompanied by exudation and scab, followed by large leafyScaleIt falls off and the exudate has a bad smell.Mucosa may have congestion, edema, erosion, etc.If such lesions are the first time,incubation periodGenerally more than 20 days.It can spread all over the body at the beginning, ormeaslesorScarlatinaSuch skin lesions occur on the basis of.The course of disease is more than one month, which is a serious type of drug eruption, often accompanied by systemic symptoms, such asAversion to cold, fever, vomiting, nausea, and some may be accompaniedLymph node enlargement、proteinuria、Hepatomegaly、jaundiceAnd other systemic symptoms.
It is the most serious type of drug eruption, which is characterized by an acute onset. The rash starts from the face, neck, and chest, with dark red, dark red, and slightly iron gray spots, which soon fuse into patches and develop to the whole body.Variously sizedRelaxationBlisterAnd the epidermis is loosened, which can be pushed with fingers, and the epidermis can be wiped off with a little force, such asScaldLike performance.Large areas of necrosis and desquamation were also found in the mucosa.Systemic toxic symptoms are serious, accompanied by high fever and visceral lesions.If the rescue is not timely, the patient may die of infection,Toxemia，renal failure，pneumoniaOr bleeding.Some patients initially showedErythema multiformeOr fixed drug eruption, which soon develops into large erythemaBulla、Epidermal exfoliation。
5. Fixed erythema
The more common type of drug eruption.The shape is special and easy to identify.The rash is characterized by limited round or oval erythema, bright red or purple red erythema, edema, and blisters can be formed in the center of severe inflammation.The damage boundary is clear, and it will be reserved laterPigment spotAfter each application of sensitizing drugs, repeated attacks occur in the same part, and some also increase new damage. The number of rashes can be single or multiple, and some are distributed throughout the body. The size of the rashes is generally 0.2 cm to several cm. The rashes can occur in any part of the body, especiallylipsAnd perioral, glans, anus, etcSkin mucosaJunction, interphalangeal skin, back of handInstepIt is commonly seen in places like Tangan.About 80% of them occur at the junction of skin and mucosa,Oral mucosaAlternativelyExanthema。Fixed drug eruptionThe regression time is generally 1 to 10 days, but mucosal erosion orulcerThe patients often have a longer course of disease, which can be delayed for tens of days before recovery.
Drug-inducedErythema multiformeThe rash is characterized by round or oval edematous erythema orpapule, as big as peasBroad beanLarge, often with blisters in the center, with purple edges,SymmetryOccurs in the limbs, often accompanied byhave a fever、Arthralgia、abdominal painWait, the serious person saidStevens Johnson syndrome, can cause erosion and pain of mucous membrane blisters.The course of disease is generally 2-4 weeks.
7. Drug hypersensitivity syndrome
It's caused by drugsIdiosyncratic reaction, characterized by fever, rash and visceral organ damage (especially liver).It may occur 7 to 28 days or more after the first application of drugs.If the drug is used again in the future, the disease may occur within one day.The initial symptom is fever, with a peak of 40 ℃.The second is perioral and facial edema, neck or systemic lymph node enlargement,Laryngitis。Skin lesions begin on the face, upper torso and upper limbs.It is erythema, papule ormeaslesThe skin rash becomes dark red gradually.Integration and progressive developmentErythroderma。
Visceral damage occurs within 1 to 2 weeks after the eruption, or up to a month.hepatitisIs the most important symptom, serumtransaminaseDifferent degrees of increase, usually nonejaundice, occursjaundiceThe prognosis is often poor.FulminantHepatic necrosisandhepatic failureIt is the main cause of death.There may also be kidneys, lungs, heartCentral nervous systemDamage.
OftenExternal medicationCause, local contact sensitivityeczemakinddermatitisAfter oral administration or injection of the same kind of drugs, the whole body may occureczemaLike skin lesions.The course of disease is usually more than one month.
Rash morphology such aseczemaThe exposed part is more serious, but it can also occur far away from the exposed sunlight.After stopping the drug, the reaction lasted for several weeks.When the drug is used again and the skin is irradiated with light, it can be aroused within 48 hourseczemaSample reaction.branchPhototoxicityandPhotosensitivityTwo.
Skin lesions are very similar clinically and pathologicallylichen planus , purplish red papule, with or without oral invasion.The skin lesions are extensive, involving the trunk and limbs.The scales are obvious, accompanied by eczema like changes. After healing, there is obvious pigmentation. After stopping the drug, the skin lesions gradually subside, and some are chronic, lasting for a long time.
The main clinical manifestations are bleeding purpura with the needle head as big as beans or larger, and the rash becomes flat or slightly raised.This rash can beThrombocytopenia, or caused by vascular injury.
It usually occurs in small blood vessels, and its inflammatory range can be from mild cell infiltration toAcute necrosisIn serious cases, the blood vessels of many organs can be invaded, including skin and kidney.Skin damageIt shows purpuraEcchymosis, nodules, necrosis, and somePolyarteritis nodosaLike lesions.Systemic manifestations include fever, arthralgia, edema, proteinuriahematuriaorrenal failure, rarelyMyositis, coronary arteritispneumoniaandGastrointestinal bleeding。
Also called acute generalized exanthematousPustulosis。The rash often begins on the face and wrinkles, and then spreads.It is a superficial, non follicular, sterile pustule with needle tip size of half a rice grain, scattered, dense, and acute.A burning or itching sensation.After stopping the medicine for a few days, it subsides, showing a large areaDesquamation。In severe cases, pustules may fuse into pus lakes.It can be accompanied by fevershiver、White blood cell countIncrease, eosinophiliaHypocalcemia、renal failureGeneral symptoms, occasional ecchymosis, purpuraErythema multiformeLike target eruptionVasculitisRashes, blisters, facial edema and mucus erosion.
It shows follicular papules and pustules, and the damage is similar to ordinaryacne。It develops slowly and often occurs more than 1 to 2 months after taking the medicine.The course of the disease is chronic and can be delayed for several months after drug withdrawal.
diagnosis
Announce
edit
The diagnosis of drug eruptions is mainly based on the medical history and clinical manifestations. Except for the characteristic manifestations of fixed drug eruptions, most drug eruptions are not easy to be distinguished from the same symptoms caused by other reasons, and must be judged by comprehensive analysis of the medical history and development process.
Clinically, we should be alert to systemic and symmetrical rashes that suddenly occur in the course of treatment, ask about the history of drug use, and pay special attention to the cross allergy of drugs and the hidden form of rashesDrug allergy。Be familiar with various types ofDrug allergyCharacteristics, excluding similar medical and dermatological diseases.Generally, the color of drug eruption is bright and itchy.Usually, the drug eruption will get better and subside quickly after stopping the sensitization drugs.
The history of drug eruption after drug use, disappearance after drug withdrawal, and recurrence during drug reuse is of great diagnostic significance.Modern immune test methods such asLymphocyte transformation test，Radioallergen adsorption test（RAST），BasophilThreshing test,macrophageWalk inhibition testwhite blood cellHistamine testIt can help us understand the immune relationship between drugs and the body, and has no practical diagnostic value.
(2) Drink more water or infusion to promote the excretion of drugs in the body.
(3) Apply to mild patientsAntihistamine、vitamin CandCalcic agent。Plus for severe patientsGlucocorticoid。For particularly serious drug eruptions, various measures should be taken as soon as possible. ①Large doses of sugarCorticosteroid hormone, for injectionMethylprednisoloneAnd gradually decrease after the condition is stable.If necessary, high dose of glucocorticoid should be given. ②Immunoglobulin for injection is generally used continuously for 3-5 days. ③Plasma exchange。
(5) Support therapy, attentionfluid infusionAnd maintaining electrolyte balance.
For those with mucosal damage, actively protect the mucosa, especially the conjunctival membrane, to preventCorneal opacificationAnd mucous membrane adhesion, children should pay attention toglansandPrepuceThe erosion, resulting in foreskin stenosis.3% daily availableBoric acid waterClean or drop corticosteroid eye drops, pay attention to the cleanness of the mouth, and rinse frequently, 2% is optionalsodium bicarbonateRinse mouth with solution.
2. Local treatment
For mild drug eruptions, it can stop itching locally, absorb erosive surface, keep clean, and heal quickly. For severe drug eruptions, it is better to dryExposure therapy（infraredLampshadeOr localRavenorWet compressOr apply PC cream externally for air disinfectionsterileBed sheets and bedding.
prevention
Announce
edit
1. When treating diseases, ask questions firstDrug allergyDo not abuse drugs that may cause drug eruption.
2. The allergy causing drugs should be clearly written inmedical recordTo draw the doctor's attention.And advise patients to avoid using the drug or some containing the drugPatent medicineAnd chemistryStructuralRelevant and easily causedcross reactionDrugs.
3. Pay attention to drug eruptionProdromal symptoms, such asfever、itchMild erythema, chest tightness, asthma, general malaise and other symptoms should be detected as soon as possible, and drugs should be stopped in time to avoid serious reactions.
fourpenicillin, tetanus antitoxinprocaineSkin test must be done before application, and all necessary medicines and measures for first aid must be prepared.
