B) Methods: We report the case of a 23-years old woman who suffered from an acute severe asthma attack complicated by asphyxic evolution leading to cardiopulmonary arrest. Cardiopulmonary resuscitation was successful, subcutaneous emphysema occurred, left pneumothorax was treated by chest tube. The clinical course was benign, and the patient returned from hospital to home after a few days with no complication. Medical history revealed that she had had asthma for 10 years, with allergy to inhaled allergens (grass pollen, house dust mites, pets dander). She had been treated 9 years earlier by subcutaneous specific immunotherapy against house dust mites for 2 years. Medications taken included albuterol, beclomethasone, salmeterol and montelukast. She ate Norway lobsters and snails 5 hours before the beginning of acute severe asthma attack and had sexual intercourse with no condom 3 hours before.
C) Results: Skin prick tests (SPT, diameters of the wheals and flares in mm) and serum specific Ig E (SSIg E, Pharmacia Unicap 1000) confirmed sensitization against snails (SPT = 7/30 ; SSIg E 7,37 kUI/l) but not against Norway lobsters (SPT = 0/0 ; SSIg E < 0,35 kUI/l) nor human seminal fluid (SPT = 0/0 ; SSIg E < 0,35 kUI/l). No Ig E sensitization was later found against prawn nor house dust mites tropomyosin (rPen a 1 < 0,35 kUI/l, Pharmacia Unicap 1000 ; rDer p 10 < 0,10 kUI/l, Phadia Immunocap 1000). No severe asthma attack did occur thirteen years after beginning of eviction diet and continuation of asthma treatment. More than 100 cases of allergic symptoms after consumption of snails among patients allergic to house dust mites were published. These allergic symptoms may occur after the first ever ingestion of snails and may be life-threatening. They begin usually 5 to 60 minutes and rarely 1 to 5 hours after the ingestion of snails (1, 2). Cross-sensitivity between snails and house dust mites is probably due to common epitopes as haemocyanin.
D) Conclusions: Allergic patients to house dust mites should be informed about the possibility of severe cross-allergy symptoms after eating snails.
1 - van Ree R et al. Asthma after consumption of snails in house-dust-mite-allergic patients: a case of IgE cross-reactivity. Allergy. 1996 Jun; 51(6): 387-93.
2 - De Maat-Bleeker F et al. Vineyard snail allergy possibly induced by sensitization to house-dust mite (Dermatophagoides pteronyssinus). Allergy. 1995 May;50(5):438-40