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Table 1 Symptoms of the acute phase of the reactions induced by drugs Modified from the NICE Clinical Guideline CG183 [59]

From: An EAACI task force report: recognising the potential of the primary care physician in the diagnosis and management of drug hypersensitivity

Type of reaction Clinical entity Symptoms
Immediate: onset usually < 1 h after drug exposure (previous exposure not always confirmed) Anaphylaxis Erythema, urticaria or angioedema and Hypotension and/or bronchospasm
Urticaria or angioedema without systemic features Wheals Angioedema
Exacerbation of asthma Dyspnea Cough Chest tightness Wheezing
Non-immediate without systemic involvement: onset usually 6–10 days after first drug exposure or within 3 days of second exposure Exanthema-like Widespread red macules or papules
Fixed drug eruption Single or multiple erythematous plaques that arise at the same site after the intake of the same drug and that resolve leaving post-inflammatory hyperpigmentation
Non-immediate reactions with systemic involvement: onset usually 2–6 weeks after first drug exposure or within 3 days of second exposure. Drug reaction with eosinophilia and systemic symptoms (DRESS) or drug hypersensitivity syndrome (DHS) Widespread red macules, papules or erythroderma Fever Lymphadenopathy Liver dysfunction Eosinophilia
Toxic epidermal necrolysis or Stevens–Johnson syndrome Painful rash and fever Mucosal or cutaneous erosions Vesicles, blistering or epidermal detachment Red purpuric macules or erythema multiforme
Acute generalized exanthematous pustulosis (AGEP) Widespread pustules Fever Neutrophilia
Other common disorders rarely caused by drug allergy Eczema Hepatitis Nephritis Photosensitivity Vasculitis