We present the clinical features with oral mite anaphylaxis by the uncommon storage mite Thyreophagus entomophagus.
Oral mite anaphylaxis
Article first published online: 10 MAR 2010
© 2010 John Wiley & Sons A/S
Volume 65, Issue 10, pages 1345–1347, October 2010
How to Cite
Sánchez-Machín, I., Glez-Paloma Poza, R., Iglesias-Souto, J., Iraola, V. and Matheu, V. (2010), Oral mite anaphylaxis. Allergy, 65: 1345–1347. doi: 10.1111/j.1398-9995.2010.02355.x
- Issue published online: 7 SEP 2010
- Article first published online: 10 MAR 2010
- Accepted for publication 28 January 2010
- food allergy;
- hidden allergens;
- NSAIDs intolerance;
- storage mites
Since the first case of oral mite anaphylaxis (OMA) was described (J Allergy Clin Immunol 1993;92:846-9), only few more cases of have been reported. The phenotype of OMA is an immediate food reaction by mite-contaminated foods (1) in patients with previous allergic rhinitis and/or asthma by sensitization to mites.
By August 2009, we compiled data of 42 patients (Table 1) with clinical history of immediate reactions to flour-based foods, suggestive of IgE-mediated hypersensitivity, and without food allergy: OMA events. All patients presented allergic rhino-conjunctivitis with/without bronchial asthma by sensitization to dust mites.
|No||Sex||Age||Atopy||Implicated food Year event*||Reaction interval||Symptoms OMA||NSAIDs intolerant||Flour mites/g|
|2||F||20||RC + A||Croquettes, Pancake/‘01||30′||U/AE/hTA/A × 2||No||1200|
|3||F||25||RC + A||Pancake, Battered foods × 2||20–30′||OAS, RC + AE × 2||No||N.D.|
|4||F||12||RC + A||Croquettes||10–15′||AE||AE||N.D.|
|5||M||39||RC||Chocolat w/cornstarch, panc’01||5′–20′||AE- AE/U||A/U/AE 2000||N.D.|
|6||M||26||RC + A||Pancake||1 h||U||No||N.D.|
|7||M||17||RC + A||Croquettes/‘00||10–15′||AE + U + A||AE/A/2000||N.D.|
|8||M||27||RC||Pancake × 2, Battered foods/‘02||5′||AE × 2, AE/U||AE/2003||960|
|9||F||45||R||Pancake × 2, Battered foods||5′||AE/U/hTA × 3||No||N.D.|
|10||F||27||RC + A||Pancake, Homemade bread||5′||AE × 2||No||N.D.|
|11||M||37||RC||Pancake, Croquettes||15′||AE/U/A × 2||No||N.D.|
|12||M||17||RC + A||Pancake||10′||AE/U/A||No||N.D.|
|13||M||16||A||Battered foods × 6/‘01||5′||U × 6||AE/2000||N.D.|
|14||F||28||RC + A||Croquettes,Battered foods,cookies||5||U, A, hTA × 3||No||N.D.|
|15||M||38||RC + A||Crepes, Pizza, Pancake/‘00||30′||hTA, U, A × 3||AE/A/1989||1067|
|17||F||22||RC + A||Battered foods||5′||A/AE||No||N.D.|
|18||M||34||RC + A||Pancake/’01||10′||RC/A/U/AE||AE/1992||N.D.|
|19||M||29||RC + A||Pancake, Croquettes/‘04||5′||AE/dysphonia||No||N.D.|
|20||F||32||RC + A||Croquettes/‘08||5′||AE/A||AE/1991||N.D.|
|21||F||42||RC||Pancake/’04 Muffins/‘05||5′||AE/dysphonia/TE × 2||AE/1991||N.D.|
|22||M||35||RC + A||Pancake, Homemade cookies/‘00||5′||AE/dysphagia/A||AE/1982||N.D.|
|24||M||35||RC + A||Homemade cookies/||5′||A/AE/U/hTA||No||N.D.|
|25||F||25||RC + A||Battered foods/‘02||15′||RC+A||AE/A 1997||N.D.|
|26||M||13||RC + A||Crepes, Homemade muffins/‘08||15′||A/U × 3||AE, 2001||104|
|29||F||15||RC + A||Hallaca* with cornstarch||2 h||AE/A||No||N.D.|
|30||M||20||RC + A||Cookies, Battered foods, Crepes||15′||AE/A/U||No||3905|
|32||F||20||RC + A||Battered food/‘08||30′||AE/U||AE/U/2005||5275|
|33||F||22||RC + A||Crepes||60′||A/U||No||33 634|
|34||F||15||RC||Homemade cookies||5′||A/U/AE/AP||No||No mites|
|35||M||57||RC||Battered foods||5′||AE/A||No||No mites|
|37||M||33||RC||Crepes/‘07||AE + A||AE/2007||N.D.|
|39||F||11||RC + A||Croquettes, Pancake/‘00||SAO × 2||AE/1999||N.D.|
|40||M||38||RC||Battered foods, Pancake/‘05||20′||AE/U||AE/2000||N.D.|
|41||F||26||RC + A||Battered foods/‘09||2 h + EIA||AE/R/A/U||AE/2001||N.D.|
|42||M||23||RC + A||Croquettes, Battered foods/‘06||5′||AE/U/A||AE/1997||N.D.|
After obtaining a written informed consent from each patient for every single test, skin prick tests (SPT) were carried out with fresh and commercial extract of involved foodstuffs including flour, milk, egg, nuts, seafood, fish, fruits, meats and spices. Specific food allergy was ruled out in all patients by negative SPT, serum-specific IgE (UniCAP; Phadia, Uppsala, Sweden) and single-blinded placebo-controlled oral challenge (SBPCOC) with every single ingredient. Study of putative flours was also completed in 11 cases, detecting mites in nine samples. Interestingly, all contaminated samples showing Thyreophagus entomophagus as the unique species.
With these results, SPT were performed with a battery of aeroallergens including common mites and T. entomophagus (Leti, Madrid, Spain). SPT with T. entomophagus were positive in all 42 patients. Five T. entomophagus-sensitized patients agreed to perform SBPCOC with T. entomophagus lyophilized extract (1 mg/ml) starting with 0.1 mg and followed by increasing twofold doses of protein extract given at 60 min intervals. Total cumulative dose was 6.8 mg (47 500 mites) of lyophilized mite extract. All five patients tolerated the challenge with no side-effects.
Non-steroidal anti-inflammatory drugs (NSAIDs) hypersensitivity diagnosis was established by SBPCOC with acetylsalicylic acid (ASA). Challenge was not performed in patients who showed at least two adverse reactions with two different NSAIDs or severe reactions. Interestingly, a positive diagnosis of NSAID intolerance was established in 21 patients (50%), who suffered episodes of periorbital angioedema with/without urticaria (five with added asthma). Nineteen patients revealed episodes of NSAIDs intolerance some years before OMA.
In this report, we have demonstrated that all patients with OMA reactions had sensitization to T. entomophagus Remarkably, T. entomophagus, which has been merely described as storage mite in German farms (2) was present in stored opened flour bags in kitchens of these sensitized patients. Differently, it has not been found, as the only species implied, by other groups studying OMA, which have recognized mites triggering allergic manifestations (1, 3) after their ingestion, even after cooking.
Up to date, group 2 of mite allergens have been suggested as the most probably implicated in OMA episodes (3) as it is resistant to low pH, heating and digestion by proteases. However, Group 1, but not group 2, has been found to be masked by flour components and binding to flour’s prolamines, resulting in an underestimation of the mite content in bakery dust (4).
In our study, mite count has been low and all the SBPCOC were negative. Consequently, there might be other causes underneath. Very interestingly, a high prevalence of NSAIDs hypersensitivity has been observed in this specific population. Furthermore, it has been noticed how acetylsalicylic acid enhances anaphylactic episodes after food intake (5). However, Blanco et al. who also found T. entomophagus in some flours in the Canary Islands, were not able to demonstrate ASA in flours (1). Sato et al. (6) found a salicylaldehyde analog identified as 2-formyl-3-hydroxybenzyl formate in opisthonotal gland secretion of Dermatophagoydes pteronyssinus. It is certainly a possibility that some infested flours by mites have also salicylaldehyde analogs with a cyclooxygenase (COX) inhibitory activity. Maybe two triggers are necessary to develop an OMA episode in a susceptible patient: intake of substance with a COX inhibitory activity and the intake of the mite proteins. More extensive studies are necessary to clarify this.