Table 1.
Comparison of advantages and disadvantages of common allergy test methods
| Type of testing | Test method advantages | Test method disadvantages |
|---|---|---|
| SPT | • Minimally invasive | • Can be uncomfortable for some patients |
| • Less patient discomfort than ID testing | • Can be contraindicated in patients with extensive skin disease, those taking certain drugs that cannot be discontinued, or those with a recent history of anaphylaxis or current pregnancy | |
| • Sensitive discrimination between positive and negative results | ||
| • When properly performed, results are highly specific | ||
| • Multiple allergens can be tested at one time | ||
| • Lower rate of systemic effects than intradermal testing | ||
| • Results available in 15 to 20 minutes | ||
| • Better correlation with allergy symptoms than in vitro test results | ||
| • Relatively inexpensive | ||
| Intradermal Testing | • More sensitive than SPT testing | • Is generally less well tolerated than SPT |
| • May be more reproducible than SPT testing | • Takes longer to perform than SPT | |
| • Provides more information on the relative sensitivity of the patient to each allergen tested | • May provide more false positive results than SPT | |
| • Results available in 15 to 20 minutes | • Requires more technical skill to deliver intradermal injections than SPT | |
| • Greater risk of systemic reactions than SPT testing & should only be used after a negative SPT result | ||
| • Like SPT, can be contraindicated in patients with extensive skin disease, those taking certain drugs that cannot be discontinued, or those with a recent history of anaphylaxis or current pregnancy | ||
| In vitro testing | • Single blood draw may be more comfortable for some patients than skin testing | • Results correlate with clinical status less well than in vivo test methods |
| • Eliminates possibility of systemic reactions | • Results from different methods may not correlate well with each other | |
| • Can be used on patients who have skin disease that interferes with skin testing | • No standardized reporting of sIgE test results available; this can mask problems with inter-assay variability | |
| • Can identify sensitivity to cross-reacting allergens | ||
| • Turn-around time for results longer than skin testing | ||
| • May be more expensive than skin test methods |