Not to be confused with the dyes Indigo carmine and Cochineal red.

Allergen Exposure

Geographical distribution

Cochineal is a natural red colour from the egg yolks and other parts of the dried female insect Dactylopius coccus Costa, a parasite of the prickly pear cactus. The insects occur in colonies covered with a fluffy wax that they secrete. The major regions of Cochineal production are South America, especially Peru, and the Canary Islands. It is an expensive colourant and is therefore not in common use: it requires 70,000 insects to make one pound of colour. The product, which in its processed form is usually called Carmine, is a crumbly solid or a powder.

Cochineal production peaked in the 1870's, but the trade declined with the introduction of synthetic, less expensive dyes. However, due to findings that synthetic red dyes may induce cancer, there has been an increasing preference for foods with natural dyes during the last decade. This, together with the strength and stability of Carmine, motivates the wide use of Cochineal in processed foods. As the colourant is of “animal” origin, it is not acceptable for use in foods for vegans or individuals keeping kosher or halaal diets.

Environment

Cochineal provides a bright strawberry-red shade to various food products. It is used in products with a pH above 3.5 and comes in water-soluble and water-insoluble forms. Carminic acid is water-soluble and provides clear orange colours in acid-based products, such as soft-drinks. Cochineal may also be used in the dyeing, printing and paint industry and may be found in lipsticks, blushes, eyeshadow, medication coatings and homeopathic medications. This colourant is not permitted in some countries.

No allergens from this substance have yet been fully characterised, but a number have been detected or isolated.

Commercial Carmine retains proteinaceous material from the source insects. These insect-derived proteins (possibly complexed with carminic acid) are responsible for IgE-mediated Carmine allergy. Several protein bands of 23-88 kDa were isolated from minced Cochineal insects. Of these, 3 protein bands were recognised by 2 of 3 Carmine-allergic patients' serum (1).

Other studies have isolated proteins of around 30, 28, and 17 kDa from raw Cochineal extract and a 50 kDa protein from boiled extract. Utilising the same technique, proteins of approximately 50 and 28 kDa were determined in the Carmine extract. Specific IgE binding bands at 17 kDa in Cochineal raw extract, at 50 kDa in boiled extract, and at 28 kDa in Carmine extract were demonstrated by IgE immunoblotting (2).

IgE-mediated reactions

In many of the reports of adverse reactions to Cochineal, the cause of sensitisation was topical exposure from the use of Carmine-containing cosmetics or occupational exposure to Carmine, and not ingestion of Carmine-containing foods and beverages. Following sensitisation, affected individuals would be sensitive to Carmine, and the amounts present in foods and beverages could elicit allergic reactions. It is not known whether all individuals with Carmine sensitivity induced through topical exposure are also sensitive to the ingestion of Carmine in foods. However, some researchers state that reactions to Carmine solely because of ingestion are likely to be exceedingly rare due to the low levels of Carmine in foods and beverages (3).

A number of instances of allergic reactions to Cochineal, including anaphylaxis, has been reported (4-6). Five individuals reacted following the ingestion of alcoholic beverages which contained this colourant (7). Anaphylaxis has been reported to Cochineal contained in yoghurt. Approximately 1.3 mg of Cochineal was present in the yoghurt (The acceptable daily intake is up to 5.0 mg per kg of body weight.) (8).

Anaphylaxis has also occurred to Cochineal contained in cosmetics (9) and in a Campari-Orange drink (10). Anaphylaxis was reported in a child after ingestion of a popsicle coloured with Carmine. A skin-specific IgE test was positive (11).

Three female patients presented with a history of anaphylaxis and/or urticaria/angioedema after ingestion of Carmine-containing foods (popsicle, artificial Crab, red Grapefruit juice). Two patients experienced an immediate, pruritic, erythematous eruption after applying a blush, coloured with Carmine, directly to facial skin, but not when the blush was used over foundation makeup (1).

Adverse effects from occupational exposure to Cochineal have also been described. Occupational asthma was described in 3 Carmine dye workers (2) and occupational asthma and rhinitis in natural dye and food processors (12).

A 35-year-old non-atopic man, who had worked for 4 years in a spice warehouse, reported asthma and rhinoconjunctivitis for 5 months related to Carmine handling in his work. He also reported a similar episode after the ingestion of a red-colored sweet containing Carmine. A double-blind oral challenge was positive (13).

In a study of 24 workers exposed to Carmine, positive skin test responses occurred to Carmine (41.7%), Cochineal (29.2%), and carminic acid (4.2%). The prevalence of sensitisation and occupational asthma caused by Carmine was 41.6% and 8.3%, respectively. When 3 workers who had left their jobs were included, the cumulative incidence of sensitisation and OA was 48.1% and 18.5% (14).

Other reactions

Extrinsic allergic alveolitis following exposure to Cochineal has been described (15).

A batch of contaminated Cochineal colourant used in food was involved in an outbreak of salmonellosis, which killed one infant and rendered 22 patients seriously ill.