Skin sensitivity to allergen does not accurately predict airway response to allergen.
BACKGROUND
Allergen challenge of the asthmatic airway has become widely applied in the study of allergic asthma in humans. Skin sensitivity correlates with inhaled sensitivity in some populations. Skin test titration has been proposed as a useful tool to guide the selection of initial allergen concentration.


OBJECTIVE
To determine the relationship between skin test sensitivity and inhaled reactivity to allergen.


METHODS
We examined the relationship between skin test and inhaled reactivity in 22 allergic asthmatic subjects. Methacholine bronchoprovocation was performed using a standardized tidal breathing technique. Prick skin test titrations were done using serially diluted lyophilized antigen extracts reconstituted in normal saline from 1:100,000 to 1:10. Inhaled allergen challenge was routinely performed in the morning using the same allergen employed in skin test titration.


RESULTS
There was no correlation between skin test threshold and the inhaled concentration required to produce a 20% fall in FEV1 (r = 0.07; P = .78). If subjects who manifested marked cutaneous reactivity (i.e., skin reactivity at dilutions greater than 1:10,000) were excluded from analysis, there was a significant correlation between cutaneous and inhaled reactivity (r = 0.84; P < .001).


CONCLUSIONS
While a correlation between skin test threshold and inhaled reactivity is present in some subjects with allergic asthma, the relationship is inconsistent.
Bowton
D L
DL
Department of Internal Medicine, Wake Forest University Baptist Medical Center, Winston-Salem, North Carolina, USA.
Fasano
M B
MB
Bass
D A
DA
D000280:Administration, Inhalation; D000328:Adult; D000485:Allergens / Q000009:adverse effects*; D001249:Asthma / Q000175:diagnosis; D001980:Bronchi / Q000187:drug effects; D001985:Bronchial Provocation Tests; D016085:Bronchoconstrictor Agents / Q000008:administration & dosage / Q000009:adverse effects; D017449:Dermatitis, Allergic Contact / Q000209:etiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000175:diagnosis; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage / Q000009:adverse effects; D008875:Middle Aged; D011237:Predictive Value of Tests; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity; D012867:Skin / Q000187:drug effects*; D012882:Skin Tests
D000485:Allergens; D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride