Usefulness of Allerkin House Dust Mite Extract for Nasal Provocation Testing

OBJECTIVES: We evaluated the clinical usefulness of Allerkin (Lofarma) for nasal provocation testing (NPT) in patients with rhinitis symptoms, by examining changes in nasal symptoms and acoustic parameters after exposure to house dust mite (HDM) extract. METHODS: Twenty patients (16 males and 4 females, mean age: 29.6±14.6 years) were enrolled. We performed skin prick test (SPT) before and 15 and 30 minutes after intranasal challenge with Allerkin HDM extract, and we evaluated symptom changes (nasal obstruction, rhinorrhea, sneezing, and itching) using a visual analogue scale. We also evaluated changes in acoustic parameters such as total nasal volume (TNV) and minimal cross-sectional area (MCA) before and after challenge. RESULTS: Group A (the nonallergic group, n=8) showed negative results for all tested aeroallergens in SPT and nonprovocative results (<25% decrease of TNV and MCA from the baseline value) in NPT. Group B (the allergic group, n=7) exhibited strongly positive results (wheal size larger than that of histamine) for HDM allergens on SPT. Group C (the local allergic group, n=5) showed negative results on SPT, but a provocative response on NPT (>29% decrease in TNV/MCA from the baseline value). Patients in group C showed significant aggravation of nasal obstruction compared to those in group A (P<0.05). Thirty minutes after HDM challenge, patients in groups B and C showed significantly greater decreases in MCA compared to those in group A (P<0.01). CONCLUSION: Allerkin HDM extract can be a useful provocative agent in NPT for diagnosing allergic rhinitis and local allergic rhinitis.