Reactions to prick and intradermal skin tests

Area of Science:

• Allergy and Immunology
• Dermatology

Background:

• Allergy skin testing is a standard diagnostic tool for atopic diseases.
• Systemic reactions (SRs) are a known, albeit infrequent, risk associated with skin testing procedures.

Purpose of the Study:

• To assess the 12-month incidence of systemic reactions (SRs) following skin prick testing (SPT) and intradermal skin testing (ST).
• To document the specific symptoms of SRs and evaluate the effectiveness of immediate intramuscular epinephrine treatment.

Main Methods:

• A prospective study involving 1,456 patients undergoing skin testing (SPT and ST).
• Systemic reactions were defined as any non-local sign or symptom attributed to skin testing (excluding vasovagal responses).
• Epinephrine (1:1,000 dilution) was administered intramuscularly to patients exhibiting any remote signs or symptoms of SRs.

Main Results:

• Overall SR incidence was 3.6% (0.4% for SPT, 3.2% for intradermal ST), with 43% of affected patients being female and 33% having asthma.
• Common symptoms included pruritic eyes/nose/pharynx, worsening cough, difficulty swallowing, nasal congestion, rhinorrhea, chest tightness, generalized pruritus, sneezing, wheeze, and urticaria.
• All patients with SRs received prompt intramuscular epinephrine, with most also receiving oral prednisone and antihistamines; no severe reactions or biphasic responses were observed.

Conclusions:

• Systemic reactions to skin testing occur in 3.6% of cases, predominantly with intradermal testing.
• Immediate intramuscular administration of epinephrine proved effective in managing all observed SRs.
• Prompt epinephrine treatment appears crucial in preventing the escalation to more severe or biphasic systemic reactions.