Core51: Drug-induced adverse reaction: sulfonamide allergy and its characterization

⚠️ High-yield / 要点：Sulfonamide allergy is often hard to recognize and may appear weeks later. Cross-reactivity between antimicrobial sulfonamides and non-antimicrobial sulfonamides is probably low.

Core features / 基本特徴

• Sulfonamide allergy can be difficult to identify.
• It may occur delayed, often weeks after exposure.
• Cross-reactivity is thought to be low between:
  • Sulfonamide antimicrobials.
  • Other sulfonamide-containing drugs.

Reaction patterns / 反応パターン

Type	Timing / features
Isolated skin reactions	Erythema, maculopapular/morbilliform rash, urticaria, pruritus; often within first 3 days
Morbilliform rash + systemic symptoms	Usually 1–2 weeks after initiation; fever, malaise, pharyngitis, atypical lymphocytosis, eosinophilia, hepatitis, nephritis, pulmonary infiltrates, cytopenias
Type I hypersensitivity	Urticaria, angioedema, bronchospasm, laryngeal edema, hypotension
Severe cutaneous reactions	Stevens-Johnson syndrome, toxic epidermal necrolysis
Other reactions	Serum sickness, hemolytic anemia, aseptic meningitis

Drugs with sulfonamide structure / スルホンアミド構造を持つ薬

Group	Examples
Antimicrobials	Sulfamethoxazole, sulfadiazine, sulfapyridine, sulfacetamide, sulfanilamide
Antidiabetics	Glyburide, glipizide, glimepiride, chlorpropamide, tolazamide
NSAIDs	Celecoxib, valdecoxib, parecoxib
DMARD	Sulfasalazine
Diuretics	Furosemide, hydrochlorothiazide, acetazolamide, brinzolamide, dorzolamide
HIV/HCV protease inhibitors	Amprenavir, fosamprenavir, darunavir, simeprevir
Others	Diazoxide, ibutilide, probenecid, sotalol, tipranavir, topiramate, zonisamide, sumatriptan

Remember / 覚え方

• Delayed rash + systemic symptoms = think sulfonamide allergy
• SJS/TEN are severe red flags
• Antimicrobial vs non-antimicrobial sulfonamide cross-reactivity is probably low