f281 Curry (Santa Maria)

Spice

A spice mixture, which may result in allergy symptoms in sensitised individuals.

Unexpected exposure

Most of the spices in Curry can be “hidden” allergens. See under Clinical Experience.

Allergen Exposure

Geographical distribution

The term "Curry" can be very confusing, as its meanings range from the name of several plants to the generic name of a considerable variety of spice mixtures and whole dishes.

"Curry" can refer simply to certain leaves, most often from 2 plants. One is a shrub, Helichrysum italicum or H. angustifolium, a member of the Asteraceae family and a relative of immortelle. Several subspecies grow in Mediterranean countries. The Curry tree is Chalcas koenigii or Murraya koenigii, of the Rutaceae family, and is native to and very common in India, especially the south, often growing wild. In South India, Curry tree leaves have been extremely prevalent as a flavouring. On that basis, the Tamil word “kari”, for “soup” or “sauce”, generated the English word "Curry". South Indian immigrants brought Curry leaves to Malaysia, South Africa and Réunion Island, but they are little known in the West.

In English usage, "Curry" refers to Eastern-style spice mixtures – powders or pastes – or the dishes they flavour, most typically vegetable or meat dishes served with rice and chutney. Curry mixtures originate in India, Sri Lanka, Myanmar, Thailand, Vietnam, Malaysia and Indonesia. They differ hugely in their ingredients and tastes, not only among but also within countries.

Curry powder was designed as a convenience flavouring for British colonial officers used to Indian food. The mixtures try to imitate the taste of Curry leaves (which quickly lose their flavour when removed from the branches). Curry pastes, on the other hand, tend to have developed without Western influence. Both pastes and powders, however, are now very widespread in the West due to cosmopolitan trends in cooking, and come in many commercial forms.

Environment

Curry powder is a mixture of 20-50 kinds of spices and herbs. Since the recipe is not traditional, the variation can be immense. Broadly speaking, but most characteristically of India, the usual base is Coriander, Cumin, Cardamom and tumeric. Other common ingredients are chili, Curry leaves, Garlic, Ginger, Onions, lemon grass, Cinnamon, Cloves, Nutmeg, Black or Cayenne Pepper, Fengreek, pandanus leaves, and Mustard seeds. Ingredients can be as unexpected as Celery, Lentil flour, galangale, Allspice, zedoary, ajwain, and radhuni.

In Thai, Malaysian, Vietnamese and Indonesian Curry pastes, Shrimp paste, Coconut or Coconut milk and various sweeteners are used regularly, lending milder and sweeter flavours. In Thai cooking Lime and Basil leaves give several Curries a distinctive taste. In Sri Lanka, Curry spices are dark-roasted, giving them a different flavour.

In excess, Curries may irritate the digestive system.

See the spices (listed under Environment) that may be components of Curry mixtures.

As Curry comprises various spices, cross-reactions would depend on the particular spices an individual is sensitised to. Nonetheless, a high correlation between the presence of skin-specific IgE to spices, especially to Curry and its components, and allergy tree pollens, fruits and vegetables has been reported, suggesting that there may be a group of cross-allergies (1).

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).