Hypersensitivity Syndrome / Drug reaction with eosinophilia and systemic symptoms (HSS/DRESS)
A review of the literature shows that there is a multitude of different names that have been used to describe this type of a severe drug reaction (e.g. sulfone syndrome, dapson syndrome, anticonvulsant hypersensitivity syndrome, dilantine syndrome, mononucleosis like illness, febrile mucocutaneous syndrome, allopurinol hypersensitivity syndrome, anticonvulsant hypersensitivity syndrome etc.)
Whereas there is ambiguity in nomenclature, there is a distinct clinical reaction pattern: The reaction often starts with fever. The patients present with a widespread skin eruption often progressing to exfoliative dermatitis, involvement of one or several internal organs ( e.g. hepatitis, pneumonitis, nephritis, myocarditis, pericarditis, myositis, pancreatits, thyroiditis)and hematologic abnormalities (eosinophilia, atypical lymphocytosis, neutrophilia, neutropenia, thrombopenia, anemia). Other findings may be lymphadenopathy, periorbital or facial edema.
This variable presentation, which may mimic many other diseases, can make the diagnosis difficult, especially as this type of drug reaction is more delayed than other drug reactions (i.e. usually 2 to 6 weeks instead of 1 to 3 weeks after the start of a certain medication). However prompt recognition of the syndrome and withdrawal of the culprit drug are essential in this potentially life-threatening , but mostly reversible reaction.
Due to the inconsistencies in reporting this subtype of the severe drug reaction, it is difficult to estimate the incidence (the reported incidence rate ranges from 1:1000 to 1:10000) and the mortality rate.
The aim of the RegiSCAR-study is in a first step to better characterize this type of reaction, to develop criteria for case definition, to elaborate an algorithm for validation of potential HSS/DRESS-cases, and in a second step to evaluate the risk of drugs.
Cases of HSS/DRESS will be recruited in the departments that are part of the existing network in each country. This means that in all countries, except from Germany where departments of pediatrics and internal medicine are already part of the network, HSS/DRESS cases will mainly be recruited from departments of dermatology and burn units.
Each national supervisor is responsible for providing the hospitals of the network with the inclusion criteria for HSS/DRESS.
Hospitalization
Reaction suspected to be drug related with
Acute skin rash
Involvement of at least one internal organ
Enlarged lymph nodes at two sites at least
Abnormalities in blood count
Fever above 38°C
At least 3 of these criteria should be present for DRESS/HSS.
After notification the interviewer should ask for more details and decide if the patient meets the required inclusion criteria.
Hospitalization
Reaction suspected to be drug related with
Acute skin rash
Involvement of at least one internal organ
Enlarged lymph nodes of at least two sites
One of the following blood count abnormalities (as reference you should use the limits provided by the lab that has done the analysis)
- lymphocytes above or below the lab limits
- eosinophils above the lab limits (in % or absolute count)
- platelets below the lab limits
Fever above 38°C
At least 3 of these criteria should be present for HSS/DRESS.
Presentation of HSS/DRESS cases
For evaluation of HSS/DRESS cases you should provide patients´ profiles containing information about:
the clinical course
the lab values
abnormalities in medical imaging
treatment of the reaction
Note:
If the liver is involved, it would be interesting, if you could gather information on bilirubin values. If they are abnormal, enter the values under the item "other biological abnormalities" on page 8 of the follow-up CRF.