For which conditions is the Skin Prick Test (SPT) recommended?

Skin Prick Testing (SPT) Recommendations by Condition

SPT is recommended for suspected bee allergy (option 3), while it has limited utility in chronic urticaria, should be avoided in severe blistering reactions to penicillin, is unreliable in dermatographism, and is contraindicated in poorly controlled asthma.

Recommended Indication

Suspected Bee Allergy (Option 3) ✓

• SPT is the primary diagnostic tool for confirming IgE-mediated allergic diseases including hymenoptera (bee) venom allergy, with sensitivity and specificity typically over 80%. 1
• SPT identifies specific IgE antibodies to bee venom allergens, helping diagnose anaphylaxis risk and guide immunotherapy decisions. 1
• Results should be correlated with clinical history of the sting reaction to confirm clinical relevance. 2, 1
• SPT can provide useful information about appropriate starting doses for venom immunotherapy. 1

Limited or Conditional Indications

Chronic Urticaria (Option 1) - Limited Utility

• While research studies show SPT positivity rates of 63-88% in chronic urticaria patients 3, 4, 5, guidelines do not recommend routine SPT for chronic urticaria because most cases are not IgE-mediated. 6
• SPT may identify sensitization to allergens (house dust mites, foods, pollens) but this rarely changes management, as chronic urticaria is typically driven by autoimmune or idiopathic mechanisms rather than specific allergen exposure. 3, 5
• The high false-positive rate (sensitization without clinical relevance) makes SPT unreliable for guiding treatment in chronic urticaria. 2

Dermatographism (Option 4) - Contraindicated

• SPT is difficult to perform and unreliable in patients with dermatographism due to non-specific wheal formation from mechanical skin trauma. 1
• In cases of prominent dermatographism, serum-specific IgE measurement is preferable over SPT. 2
• The physical pressure of the lancet itself triggers whealing, making interpretation impossible. 2

Contraindicated Situations

Severe Blistering Reaction to Penicillin (Option 2) - Avoid SPT

• SPT should not be performed in patients with history of severe cutaneous adverse reactions (blistering, Stevens-Johnson syndrome, toxic epidermal necrolysis) as it may precipitate dangerous reactions. 2
• Severe blistering reactions suggest non-IgE-mediated mechanisms (Type IV hypersensitivity or severe cutaneous adverse drug reactions) where SPT is not diagnostically useful. 2
• For suspected penicillin allergy with severe reactions, serum-specific IgE testing for penicilloyl determinants is safer, though sensitivity is limited. 2
• Intradermal testing carries even higher risk and should be avoided in this context. 2

Poorly Controlled Asthma (Option 5) - Contraindicated

• Patients with poorly controlled asthma are at increased risk for systemic reactions including anaphylaxis during SPT, making it a relative contraindication. 1, 7
• Asthma should be optimized before performing SPT, as severe bronchospasm can complicate allergic reactions to testing. 7
• If allergy testing is essential, in vitro specific IgE blood tests should be used instead until asthma control improves. 1
• Emergency equipment must be available, and β-agonists should be readily accessible. 2, 1

Critical Testing Considerations

When SPT is Appropriate

• SPT is indicated for IgE-mediated allergic conditions: allergic rhinitis, asthma with suspected allergic triggers, food allergy, drug allergy (non-severe), venom allergy, and latex allergy. 2, 1, 7, 6
• Antihistamines must be discontinued several days before testing; oral/inhaled steroids do not need discontinuation. 2, 1
• Positive results (wheal ≥3 mm) indicate sensitization but require clinical correlation to confirm true allergy. 2, 6
• Negative predictive value is high (>95%), making negative tests useful to rule out IgE-mediated allergy. 2

Safety Precautions

• Systemic reactions including anaphylaxis are extremely rare but possible, requiring emergency equipment availability. 1, 7
• Avoid SPT in patients on β-blockers due to risk of severe, refractory anaphylaxis; use blood testing instead. 1
• Never perform SPT based solely on screening panels without clinical history suggesting specific allergen exposure. 2