IgE-mediated reactions
Spices may uncommonly induce symptoms of food allergy in sensitised individuals (2). Symptoms are usually mild but vary from itching and smarting of the lips and mouth to anaphylaxis (1). Most allergic reactions produced by spices are the result of ingestion, and spices usually act as “hidden” allergens (1, 3). Spices as hidden allergens are potentially very dangerous because minute amounts can cause systemic reactions and even anaphylactic shock (4).
The increasing use of spices in cosmetics has led to more-frequent reports of allergic skin reactions, including contact dermatitis and contact urticaria (5-7).
Powdered spices may cause occupational allergic respiratory symptoms even in non-atopics (3).
It must be kept in mind that spices contain, besides allergens, a number of pharmacologically active and/or toxic compounds, which may cause irritation and inflammation leading to intolerance reactions; these must not be mistaken as food allergy (8).
Curry may commonly induce symptoms of food allergy or skin allergy in sensitised individuals (9-11). As with spice reactions generally, symptoms, though usually mild, vary from itching and smarting of the lips and mouth to anaphylaxis (1). Reactions due to skin contact and inhalation have been reported (12). Curry, like other powdered spices, may cause occupational allergic respiratory symptoms even in non-atopics (3).
A number of studies have evaluated the prevalence of Curry and spice hypersensitivity (13).
In a study in which scratch tests with common spices were performed on 1,120 atopic and 380 non-atopic patients, positive reactions were seen almost exclusively in atopic individuals. Curry and Paprika produced reactions most frequently. Of 1038 atopic patients tested for skin-specific IgE to Curry, 181 were positive, and 1 of 335 non-atopics was positive. When the components of Curry were tested separately, Coriander, Caraway, Cayenne and Mustard were responsible for the vast majority of the skin reactions, producing positive reactions in at least 1 in every 3 patients. Clinical symptoms to ingested spices were noted by 5 patients. When small amounts of spices were spread on the oral mucosa, local reactions, especially in the mouth and nasopharynx, were reported in 14 out of 35 unselected patients with positive skin test reactions (1).
When serum-specific IgE antibodies against Coriander and/or Curry, Mace, Celery, and White pepper were measured in 150 patients with suspected food allergies, it was found that 15% of the 288 spice-specific IgE tests performed resulted in = 10% binding of anti-IgE. Out of 12 sera studied in detail, IgE antibodies directed against various spices were present in most, and all 12 contained IgE against Mugwort pollen allergen extract. The study suggests that IgE against various spices may play a role in some adverse reactions to food (14).
Allergic contact dermatitis, with a positive patch test, has been described (13).
In a study of patients with skin allergy, 6 of 106 who were allergic to Balsam of Peru were patch test positive for Curry, whereas none of 170 patients not allergic to Balsam of Peru were patch test positive to Curry (15).
A number of reports have described anaphylaxis to Curry. Anaphylaxis to Curry powder was reported in a 26-year-old nurse who developed severe bronchospasm. Initial symptoms were generalised itching, diarrhoea and stridor, which were reproduced 20 minutes after an oral challenge of Curry and Rice. The causative allergens in the Curry were narrowed down to Cardamom and Fenugreek. Serum-specific IgE to both were high (16). Severe anaphylaxis to Mustard masked in a "chicken dip" occurred in a 38-year-old woman in a fast food restaurant. Skin-specific IgE was detected to Mustard, Coriander, and Curry powder, which often contains Mustard (17).
Curry may also cause idiopathic anaphylaxis not obviously apparent from testing with the common food allergen panel (18).
Curry may result in hypersensitivity reactions in individuals working in the food industry. A 26-year-old man, working with a variety of spices in the food industry, developed asthma and rhinitis on inhalation of dust from spices during the working week. In his third year at the factory, symptoms progressed to severe dyspnoea with wheezing, especially at night. Skin-specific IgE tests for Curry, Coriander, and Mace were strongly positive. Serum-specific IgE antibodies against Coriander, Curry, Mace, Ginger, and Paprika powder could be demonstrated. Leukocytes from a normal donor, after passive sensitisation with serum from this patient, released a substantial amount of histamine on challenge with extracts of Coriander, Mace, and Curry powder. The authors concluded that inhalation of dust from spices can result in an IgE-mediated allergy to these substances (19).
Contact dermatitis to a spice mix was reported in a 39-year-old-butcher. The patient underwent skin-specific IgE evaluation, with scratch-patch testing with spice mix containing glutamate, Paprika and other spices. Specific serum IgE was measured with CAP-FEIA. Skin-specific IgE was detected for Mugwort and Camomile, and lower levels for the spices Paprika, Curry, and Cumin. Scratch-patch tests were negative for different meats, but strongly positive for spice mix after 30 minutes and positive after 48 hours (infiltration and vesiculation occurred). Specific IgE was slightly elevated for Paprika (0.47 kU/L), Anise (0.43 kU/L), Curry (0.36 kU/L) and Mugwort (3.83 kU/L). The tests performed thus demonstrated an IgE-mediated contact allergy to spices but also a delayed-type allergy to spice mix as a manifestation of Mugwort-spice syndrome in this individual. The authors suggested that when testing for occupational dermatitis in butchers, clinicians should also take protein contact allergy to spices into consideration (20).
Protein contact dermatitis was reported in a 60-year-old man who had worked as a cook for 20 years and then become a painter. He developed an irritant contact dermatitis of his forearms due to repeated contact with lye. Once recovered, he became a cook again, but 2 weeks later developed itching of the palms, followed by a rash, after contact with spices. Tests with uncooked Curry and Paprika were positive, and to cooked Paprika. Serum IgE to Curry was negative (12).
Other reactions
Non-allergic, irritant reactions from this and other spices are common.
In patients with positive patch test results to Balsam of Peru and/or a perfume mixture, who had chronic dermatitis of a morphology consistent with endogenous dermatitis, the food items most commonly mentioned as causing aggravation of symptoms on at least 3 different occasions were wine, candy, chocolate, Cinnamon, Curry, citrus fruit, and flavourings (21).
