1. Time interval to reaction	a) In already sensitized patients
	-> immediate reaction	immediate to 60 min
	-> delayed (non-immediate)	> 1 h-several weeks
	b) In de novo sensitization while on treatment
	-> Typical sensitization latency	5–10 Days
2. Clinical manifestations	a) Immediate-type symptoms: e. g., flushing, urticaria, angioedema, bronchospasm, anaphylaxis
	b) Delayed-type symptoms: maculopapular drug eruptions, acute generalised exanthematic pustulosis (AGEP), severe cutaneous adverse reactions: Stevens-Johnson-Synrom (SJS), toxische epidermale Nekrolyse (TEN), „drug reaction with eosinophilia and systemic symptoms“ (DRESS)
	c) Specific symptoms: e. g., hepatitis, cytopenias, autoimmune diseases (e.g., lupus erythematosus, Ig-A dermatosis)
3. Pathomechanisms	a) Immunological hypersensitivity reaction: immediate-type (type I according to Coombs and Gell, mostly IgE-mediated): typical manifestation, immediate-type symptoms	Reaction time: 0–6 h (in rare cases, up to 12 h)
	b) Non-immunological hypersensitivity reaction: typical manifestation, immediate-type symptoms	Reaction time: 0–6 h (in rare cases, up to 12 h)
	c) Immunological hypersensitivity reaction: delayed-type (type IV according to Coombs and Gell, T cell-mediated): typical manifestation, delayed-type symptoms	Reaction time: 24–72 h (in rare cases, after 6 h)
	d) Other immunological hypersensitivity reactions (type II, type III according to Coombs and Gell, IgG-, IgA, or IgM-mediated): cytopenias, serum sickness, allergic vasculitis	Reaction time: from 24 h
	In new sensitization under treatment	Typical sensitization latency: 5–10 days in type I–IV, rarely longer: weeks to months, e. g., in SJS/TEN, DRESS, autoimmune diseases (e. g., lupus erythematosus)