Drug hypersensitivity syndrome

There are many diseases with similar symptoms, and if the diagnosis is based solely on the surface of the symptoms, it may be a misdiagnosis. Drug hypersensitivity syndrome is such a disease, which is easy to misdiagnose because of its unknown incidence and diverse clinical manifestations. So what are the diagnostic criteria and treatment methods for drug hypersensitivity syndrome? Popularize relevant content to everyone and learn more medical knowledge.

Drug hypersensitivity syndrome, also known as drug rash with eosinophilia and systemic symptoms or drug-induced delayed multiple organ hypersensitivity syndrome, is an acute and severe adverse drug reaction with the triple symptom of fever, rash, and visceral involvement.

The exact incidence of DRESS is unknown (about 1 in 10,000 for antiepileptic drugs and sulfonamides), the mortality rate is high, up to 10%, the clinical manifestations are diverse, and it is easy to misdiagnose.

Common drugs that cause DRESS syndrome include antiepileptic drugs (phenobarbital, carbamazepine, lamotrigine), antibiotics (minocycline, β-lactams, sulfonamides, abacavir, nevirapine), allopurinol, dapsone, sulfasalazine, thyroxine, and fluindione. In recent years, there have been reports of DRESS caused by aspirin, strontium ranelate, atorvastatin, vancomycin, etc.

1. Diagnostic Criteria

The main ones are the 2006 Japanese Drug Review Group diagnostic criteria and the 2007 RegiSCAR diagnostic criteria. Japanese Drug Review Panel Diagnostic Criteria (2006)

① Maculopapular rash that occurs more than 3 weeks after using certain specific medications

② After stopping the causative drug, symptoms persist for more than 2 weeks

③Body temperature higher than 38℃

④Accompanied by liver function impairment (glutamate aminotransferase> 100 U/L)

⑤Accompanied by one or more of the following hematological changes:

a. Increased white blood cell count (> 11 × 109 /L)

b. The presence of atypical lymphocytes (> 5%)

c. Eosinophils increased (> 1.5 × 109 /L)

⑥Enlarged lymph nodes

⑦ HHV-6 reactivation

Typical DIHS/DRESS: all the above items are present; atypical DHS: (1-5) items are present, among which item 4 may also manifest as damage to other organs (such as kidney damage).

2. Treatment Methods

Early diagnosis is a key step in treatment and is also crucial to the patient's prognosis. Mainly include:

1 Routine treatment: Immediately stop using the allergenic drug, hospitalize for treatment, drink plenty of water or receive fluid infusion to promote the excretion of the allergenic drug. At the same time, the experimental use of antibiotics or nonsteroidal anti-inflammatory drugs should be avoided in the acute phase to prevent cross-reactions between drugs from masking the original clinical symptoms or aggravating the original symptoms. The use of similar drugs should also be avoided.

2. Application of glucocorticoids The initial dose of glucocorticoids can be determined according to factors such as the different drugs causing the disease, the condition of the underlying disease and the age of the patient. Usually, methylprednisolone 1g/d is administered intravenously. For patients with immunosuppression or severe infection, it is recommended to use a half-dose shock first, that is, methylprednisolone 0.5g/d is administered intravenously for 3 consecutive days, and then changed to methylprednisolone 1g/d, administered intravenously for 3 consecutive days. Then gradually decrease. A commonly used dose is prednisolone (40-60) mg/d, and the dose is adjusted according to clinical manifestations. Hormones are generally taken for several weeks to several months. There are reports that the condition will be aggravated when the immunosuppressant cyclophosphamide is used simultaneously. Therefore, the use of immunosuppressants should be carefully considered when using high-dose hormones in clinical practice.

3. Intravenous immunoglobulin: For patients with immunosuppression or severe infection who are not suitable for glucocorticoid pulse therapy, as well as patients with severe DRESS who are ineffective with glucocorticoid pulse therapy, high-dose immunoglobulin therapy is appropriate. The general dosage is immunoglobulin (10-20) g/d, i.e. (0.2-0.4) g/ (kg·d), intravenous drip for 3 days; if the effect is not obvious, the dose can be increased to (30-40) g/d, i.e. (0.6-0.8) g/ (kg·d), for a total of 3 days. Combined use of glucocorticoids is superior to high-dose pulse immunoglobulin therapy alone.

4 Antiviral treatment is very important for HHV-6 reactivation, especially for DRESS accompanied by cerebrospinal meningitis.