Drug allergy laboratory findings

Jump to navigation Jump to search

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Charmaine Patel, M.D. [2]

Drug Allergy


Patient Information





Differentiating Drug allergy from other Diseases

Epidemiology and Demographics

Risk Factors


Natural History, Complications and Prognosis


History and Symptoms

Physical Examination

Laboratory Findings

Other Diagnostic Studies


Medical Therapy

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Drug allergy laboratory findings On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides


American Roentgen Ray Society Images of Drug allergy laboratory findings

All Images
Echo & Ultrasound
CT Images

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Drug allergy laboratory findings

CDC on Drug allergy laboratory findings

Drug allergy laboratory findings in the news

Blogs on Drug allergy laboratory findings

Directions to Hospitals Treating Drug allergy

Risk calculators and risk factors for Drug allergy laboratory findings


Drug allergy is primarily a clinical diagnosis based on the patient history, and a thorough physical exam. Certain laboratory findings may be seen during the acute phase of the reaction, but are not always specific. Skin testing and biopsies can be performed when there is not a clear diagnosis.

Laboratory Findings

  • Erythrocyte sedimentation rate (ESR) may be increased.
  • White blood cell (WBC) may be increased.
  • Urine eosinophils may be increased, especially in cases of allergic interstitial nephritis.
  • Blood eosinophils may be increased, especially in cases of drug induced TEN.
  • Liver function tests (LFT)'s may be increased.
  • Elevations in tryptase may be seen detected in serum or plasma within several hours after an acute allergic event, and is consistent with anaphylaxis.
  • Histamine levels may be elevated after an acute reaction, but is unreliable for diagnosis.
  • Complete blood count – a complete blood count (CBC) is useful in ruling out hemolytic type II drug reactions, such as hemolytic anemia, thrombocytopenia or neutropenia.
  • Coombs test- the indirect and direct Coomb’s test is used to determine the presence of antibodies on red cell membranes. This test can also be useful in confirming hemolytic anemia. [1]
  • Basophil activation test- this test quantifies the activation of basophils using flow cytometry. Basophils are implicated in the development of both immune and non-immune mediated drug reactions. Some studies have shown that this test is useful in evaluating allergy towards beta-lactam antibiotics, muscle relaxants, and NSAIDS, however further studies are needed before this type of testing is widely accepted as a diagnostic tool. [2]


  1. Schnyder B (2009). "Approach to the patient with drug allergy". Immunol Allergy Clin North Am. 29 (3): 405–18. doi:10.1016/j.iac.2009.04.005. PMID 19563988.
  2. Hausmann OV, Gentinetta T, Bridts CH, Ebo DG (2009). "The basophil activation test in immediate-type drug allergy". Immunol Allergy Clin North Am. 29 (3): 555–66. doi:10.1016/j.iac.2009.04.011. PMID 19563997.

Template:WikiDoc Sources