Calculators · Dermatology · Criteria

RegiSCAR DRESS validation score

Also called RegiSCAR, DRESS score, DIHS score, drug reaction with eosinophilia and systemic symptoms

Classifies a suspected DRESS case as no case, possible, probable or definite (score −4 to 9).

Fever ≥38.5 °C
Enlarged lymph nodes (>1 cm, ≥2 sites)
Eosinophilia

If leucocytes <4 × 10⁹/L, use %: 10–19.9% = +1, ≥20% = +2.

Atypical lymphocytes
Skin rash extent >50% BSA
Rash suggestive of DRESS (≥2 of: facial oedema, infiltration, purpura, scaling)
Skin biopsy suggestive of DRESS
Internal organ involvement (other causes excluded)
Resolution in ≥15 days
Alternative causes excluded (≥3 tests negative, none positive: ANA, blood culture, HAV/HBV/HCV serology, Chlamydia/Mycoplasma)

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Formula and scoring

Fever ≥38.5 °C: no/unknown −1, yes 0. Lymph nodes +1. Eosinophils 0.7–1.499 ×10⁹/L +1, ≥1.5 +2. Atypical lymphocytes +1. Rash >50% BSA +1. Suggestive rash: yes +1, no −1. Biopsy not suggestive of DRESS −1. Organs: one +1, ≥2 +2. Resolution ≥15 days: no/unknown −1. ≥3 negative tests for other causes +1. Total −4 to 9: <2 no case, 2–3 possible, 4–5 probable, >5 definite.

Exam and ward pearls

  • Typical latency is 2–8 weeks after starting the drug (median 22 days in RegiSCAR); anticonvulsants and allopurinol head the list.
  • Commonest culprits in RegiSCAR: antiepileptics (35%), allopurinol (18%), sulfonamides/dapsone (12%).

When not to rely on it

  • Several items (resolution time, organ involvement) are only known later, so early scores under-call DRESS — rescore as data arrive.

Source

  1. Kardaun SH, Sidoroff A, Valeyrie-Allanore L, et al. Variability in the clinical pattern of cutaneous side-effects of drugs with systemic symptoms: does a DRESS syndrome really exist? Br J Dermatol. 2007;156(3):609-11. doi:10.1111/j.1365-2133.2006.07704.x · PMID 17300272
  2. Kardaun SH, Sekula P, Valeyrie-Allanore L, et al. Drug reaction with eosinophilia and systemic symptoms (DRESS): an original multisystem adverse drug reaction. Results from the prospective RegiSCAR study. Br J Dermatol. 2013;169(5):1071-80. doi:10.1111/bjd.12501 · PMID 23855313
  3. Manieri E, Dondi A, Neri I, Lanari M. Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome in childhood: a narrative review. Front Med (Lausanne). 2023;10:1108345 (Table 2: RegiSCAR items, score range −4 to 9). doi:10.3389/fmed.2023.1108345 · PMID 37575981

Formula and cut-offs checked against these sources on 8 Nov 2026. Educational tool for clinicians; it does not replace clinical judgement.

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