View metadata, citation and similar papers at core.ac.uk brought to you by CORE

provided by Elsevier - Publisher Connector

The Role of Allergens and Pseudoallergens in Urticaria

Torsten Zuberbier Department of Dermatology and , ChariteÂ, Humboldt University, Berlin, Germany

Adverse reactions to food are a frequently discussed urticaria pseudoallergic reactions against NSAID are cause of urticaria. In acute urticaria 63% of patients responsible for approximately 9% of cases, and in a suspect food as the eliciting factor; however, this subset of patients with chronic urticaria a diet low in cannot be con®rmed in prospective studies. In adults pseudoallergens has been proven to be bene®cial in the rate of type I allergic reactions is below 1%, several studies, with response rates observed in more although in children the percentage appears to be than 55% of patients. Double-blind, placebo-con- higher. Also in chronic urticaria type I allergic reac- trolled challenge tests have shown that arti®cial food tions play only a minor role as an eliciting factor. additives are not only to blame, with the majority of The same holds for the physical urticarias. The role reactions being traced back to naturally occuring of pseudoallergic reactions has not been investigated pseudoallergens in food. Key words: angioderma/hyper- for all types of urticaria, but apparently they are not sensitivity/intolerance/wheal. Journal of Investigative important in physical urticarias; however, in acute Dermatology Symposium Proceedings 6:132±134, 2001

oth allergic and pseudoallergic reactions have fre- evidence for 0 of 50 and 1 of 109 patients, respectively. In quently been discussed as possible eliciting factors in childhood type I allergy appears to be of higher importance, with a various forms of urticaria; however, only a limited rate of 15% reported in the age group of 6 mo to 16 y (Kauppinen number of controlled studies are available. Epidemio- et al, 1984). Blogic studies are dif®cult to perform for several reasons. Pseudoallergic reactions against food were not reported in any of First, in urticaria not only must the elicitation of whealing by one the studies, but pseudoallergic reactions against NSAID were factor be considered, but also the augmentation of pre-existing low reported to be the second most frequent cause, responsible for 9% level disease activity by allergens or pseudoallergens. Second, the of cases (Zuberbier et al, 1996). diagnosis of allergy and pseudoallergy is complicated. Whereas in type I allergic reactions skin and blood tests are available, skin tests especially may lead to falsely positive answers in urticaria patients CHRONIC URTICARIA due to unspeci®c whealing. The gold standard remains the double- Similar to acute urticaria, type I allergic reactions are only rarely blind, placebo-controlled allergen challenge. In pseudoallergic responsible for the development of chronic urticaria (Juhlin, 1981; reactions the situation is even more complicated as to date no Zuberbier et al, 1995). The most likely subgroup of chronic skin or in vitro test is available. The clinical symptoms cannot be urticaria where type I allergy can be suspected are those patients distinguished from a type I allergic reaction; however, for who suffer from intermittent attacks of whealing lasting for a few provocation tests it must be remembered that in contrast to type hours shortly after the ingestion of food. In contrast, in patients I , symptoms occur frequently with a latency of more than with chronic continuous urticaria with daily whealing the type I 4 h and symptoms cease frequently only after an omission of the allergen is very unlikely to be responsible. In this subset of patients suspected pseudoallergen for more than 10±14 d. The latter pseudoallergic reactions against food and food additives have been observation is especially important in comparing different studies repeatedly discussed in the past apart from infectious or using elimination diets. autoimmune etiology. A survey of studies is summarized in Table I; however, only a few studies have used the gold standard of double-blind, placebo-controlled food challenge tests. Results ACUTE URTICARIA may also differ due to the differences in study populations and study Acute urticaria is a frequent disease affecting approximately 15%± conditions. Some studies have included not only patients with 23% of the population at least once in their life time (Henz et al, chronic urticaria but also patients with physical urticaria. In other 1998). Asked for the eliciting cause, most patients suspect an cases elimination diets were only used for a short period of a few allergy against food (63%) (Zuberbier et al, 1996); however, this days. Our own results (Zuberbier et al, 1995) show that in those assumption could not be con®rmed in two studies (Aoki et al, patients improving on a diet low in pseudoallergens, 30% show 1994; Zuberbier et al, 1996) where could only give a decrease of symptoms after only 10±14 d on the diet. Approximately 50% of patients do not show a total clearance of symptoms but have an improvement in disease intensity, pointing Manuscript received June 19, 2001; accepted for publication June 19, to other possible cofactors involved in the pathogenesis. In some 2001. countries referrals to specialists are only possible in severe cases. In Reprint requests to: Prof. Dr. T. Zuberbier, Department of our own study unselected patients with chronic continuous Dermatology and Allergy, Charite Campus Mitte, Schumannstr. 20/21, urticaria were included who had not previously received a D-10117 Berlin, Germany. Email: torsten.zuberbier@chariteÂ.de diagnostic work-up. In this group a high incidence of pseudo-

1087-0024/01/$15.00 ´ Copyright # 2001 by The Society for Investigative Dermatology, Inc. 132 VOL. 6, NO. 2 NOVEMBER 2001 ALLERGENS, PSEUDOALLERGENS, AND URTICARIA 133

Table I. Survey of studies on the role of food in the pathogenesis of urticaria

Number of Number of positive patients reactions to Author(s) investigated food additives Method of provocation Response to diet

Warin and Smith (1976) 111 59.5% (incl. ASS) single-blind, placebo-controlled 75%a (antihistamine treatment) Genton et al (1985) 17 88.2% (incl. ASS) single-blind 93.3%a Michaelsson and Juhlin (1973) 52 75% (incl. ASS) single-blind 81.3% free of symptomsa 6.3% clear improvementa Thune and Granhold (1975) 100 62% (incl. ASS) single-blind 80.6% clear improvementa 19.4% spontaneous clearancea WuÈthrich and Fabro (1981) 620 26.6.% (incl. ASS) single-blind > 60% clear improvementa Juhlin (1981) 330 31% single-blind no data Ortolani et al (1984) 70 59.6% (incl. ASS) single-blind, placebo-controlled no data Rudzki (1980) 158 31.6% no data Ros et al (1976) 75 follow-up study 24% free of symptomsa 57% clear improvementa Verschave et al (1983) 67 none 55% of all patients Gibson and Clancy (1980) 76 up to 54% single-blind, placebo-controlled of all patients: 71.1% free of symptoms 19.7% clear improvement 9.2% refused diet Kirchhof et al (1982) 100 39% double-blind, placebo-controlled 44%a Suprananiam and Warner (1986) 43 24% double-blind, placebo-controlled 87.5%a Zuberbier et al (1995) 67 19% double-blind, placebo-controlled 73% of all patients Pigatto and Valsecchi (2000) 202 of a 37.3% double-blind, placebo-controlled 62.4% clear improvement total group 17.3% no bene®t of 348 20.3% discontinued diet

aNumber referring to the group of patients put on diet after positive reactions. allergic reactions against food was seen. These results were only REFERENCES recently con®rmed by Pigatto and Valsecchi (2000), who inves- Aoki T, Kojima M, Horiko T: Acute urticaria: history and natural course of 50 tigated a group of 202 patients with chronic urticaria using the same patients. J Dermatol 21:73±77, 1994 diet. In this study 126 patients improved on the diet, whereas 35 BuÈhner S, Ehlers I, KuÈhl F, Zuberbier T, Lochs H: Gastrointestinal barrier in patients patients did not show any bene®t from the diet and 41 patients with chronic recurrent urticaria: in¯uence of a low-pseudoallergen diet. Gastroenterology 114:A868, 1998 dropped out. In both studies reactions to food additives were only Fiebiger E, Hammerschid F, Stingl G, Maurer D: Anti-FceRI-a autantibodies in seen in a minority of patients (19% and 37%, respectively), which autoimmune-mediated disorders. J Clin Invest 101:243±251, 1998 points at the relevance of naturally occuring pseudoallergens. Genton C, Frei PC, PeÂcoud A: Value of oral provocation tests to aspirin and food Especially aromatic compounds found in vegetables and food additives in routine investigation of and chronic urticaria. J Allergy Clin Immunol 76:40±45, 1985 appear to be important. An open provocation test in 31 chronic Gibson A, Clancy R: Management of chronic idiopathic urticaria by the urticaria patients showed that 71% of patients responding to a low identi®cation and exclusion of dietary factors. Clin Allergy 10:699±704, 1980 pseudoallergen diet reacted to tomatoes, and 44% to distillates of Henz BM, Zuberbier T, Grabbe J, Monroe E, eds: Urticaria. Clinical, Diagnostic and Therapeutic Aspects. Berlin: Springer, 1998 tomatoes containing aromatic compounds free of protein and Hide M, Francis DM, Grattan GEH, Hakimi J, Kochan JP, Greaves MW: salicylic acid. In contrast less than 7% reacted to , protein, Autoantibodies against the high-af®nity IgE receptor as a cause of histamine and salicylate-rich residue (Pfrommer et al, 1996). release in chronic urticaria. N Engl J Med 328:1599±1604, 1993 During the last few years very little knowledge has been gained Juhlin L: Recurrent urticaria: clinical investigation of 330 patients. Br J Dermatol 104:369±381, 1981 about the mechanisms of pseudoallergic reactions against food. Kauppinen K, Juntunen K, Lanki H: Urticaria in children. Retrospective evaluation Synergism with other eliciting factors might be of importance; one and follow-up. Allergy 39:469±472, 1984 possibility appears to be the gastric mucosa. Initial results show that Kirchhof B, Haustein UF, Rytter M: AzetylsalizylsaÈure-Additiva-Intoleranz- the gastric but not the intestinal permeability is decreased in patients phaÈnomene bei chronisch rezidivierender Urtikaria. Dermatol Monatsschr 168:513±519, 1982 with chronic continuous urticaria bene®ting from a pseudoaller- Michaelsson G, Juhlin L: Urticaria induced by preservatives and dye additives in food gen-free diet, and this pathologic permeability is restored after 3 wk and drugs. Br J Dermatol 88:525±532, 1973 of diet (BuÈhner et al, 1998). In another study we investigated the Ortolani C, Pastorello E, Luraghi MT, Della Torre F, Bellani M, Zanussi C: occurence of anti-FceRI-a autoantibodies, which have been Diagnosis of intolerance to food additives. Ann Allergy 53:587±591, 1984 Pfrommer C, Bastl R, Vieths S, Ehlers I, Henz BM, Zuberbier T: Characterization of described to be of pathophysiologic relevance in some patients naturally occurring pseudoallergens causing chronic urticaria. J Allergy Clin with urticaria (Hide et al, 1993; Fiebiger et al, 1998). In our studies Immunol 1/3:367, 1996 these autoantibodies were found at the same frequency as described Pigatto PD, Valsecchi RH: Chronic urticaria: a mystery. Allergy 55:306±308, 2000 Ros AM, Juhlin L, Michaelsson G: A follow-up study of patients with recurrent earlier, but they could be found both in patients with idiopathic urticaria and to aspirin, benzoates and azo dyes. Br J Dermatol chronic urticaria (seven of 22) and in patients with pseudoallergy 95:19±24, 1976 against food whose symptoms cleared on stopping the diet (six of Rudzki E, Czubalski K, Grzywa Z: Detection of urticaria with food additives 17) (Zuberbier et al, 2000). There are two possible explanations for intolerance by means of diet. Dermatologica 161:57±62, 1980 Supramaniam G, Warner JO: Arti®cial food additive intolerance in patients with these ®ndings. First, the FceRI-a autoantibodies are not of angio-oedema and urticaria. Lancet II:907±909, 1986 pathophysiologic relevance in all patients with urticaria; and Thune P, Granholt A: Provocation tests with antiphlogistica and food additives in second, a synergism between the autoantibodies and other eliciting recurrent urticaria. Dermatologica 151:360±367, 1975 stimuli, e.g., food, is necessary for the appearance of clinical Verschave A, Stevens E, Degreef H: Pseudo-allergen-free diet in chronic urticaria. Dermatologica 167:256±259, 1983 symptoms in some patients. Future research in this ®eld is necessary Warin RP, Smith RJ: Challenge test battery in chronic urticaria. Br J Dermatol to answer this question. 94:401±405, 1976 134 ZUBERBIER JID SYMPOSIUM PROCEEDINGS

WuÈthrich B, Fabro L: AcetylsalicylsaÈure- und Lebensmitteladditiva-Intoleranz bei Zuberbier T, Fiebiger E, Maurer D, Stingl G, Henz BM: Anti-FceRIa serum Urtikaria, Asthma bronchiale und chronischer Rhinopathie. Schweiz Med Wschr autoantibodies in different subtypes of urticaria. Allergy 55:951±954, 2000 111:1445±1450, 1981 Zuberbier T, If¯aÈnder J, Semmler C, Czarnetzki BM: Acute urticaria ± clinical Zuberbier T, Chantraine-Hess S, Hartmann K, Czarnetzki BM: Pseudoallergen-free aspects and therapeutical responsiveness. Acta Derm Venereol (Stockh) 76:295± diet in the treatment of chronic urticaria ± a prospective study. Acta Derm 297, 1996 Venereol (Stockh) 75:484±487, 1995