Clove is a spice which may result in allergy symptoms in sensitised individuals.

Clove Allergy Test: Allergen Exposure

The clove tree is native to the Moluccas (previously known as the Spice Islands), however today it is grown in tropical climates around the world. They have been used by humans for their essential oil for thousands of years, having been recorded by the ancient Egyptians and Romans.

Cloves are an important ingredient in a variety of national cuisines. In North Africa they are widely used to flavour meat and rice dishes, and are used similarly in Sri Lanka. In Ethiopia they are roasted along with coffee beans.

In Europe cloves are traditionally combined with cinnamon in some pastries and stewed fruits, as well as in the production of mulled wine or cider. They are also found in certain stews and pickles. The most common flavouring method in the West is to simmer whole cloves with fish, poultry, game and meat.

They are a common ingredient in spice mixes such as curry paste and the Mexican mole sauces. Cloves are also a key ingredient in the British Worcestershire sauce.

In Indonesia cloves are primarily used to produce clove cigarettes, or kretek. In recent years these have become increasingly popular in Western countries.

Clove oil is widely used as an analgesic and antiseptic agent in dentistry, and is often found in toothpaste and tooth powders. It is also a flavouring, scent or deodorant in a range of products, including perfumes, soaps and detergents.

Clove oil has also been used medicinally in the treatment of digestive ailments, as well as fungi and parasites.

Clove Allergy Test: Allergen Description

No allergens present in clove have been characterised to date.

Clove Allergy Test: Potential Cross-Reactivity

Cross-reactivity can be expected among the different species of the genus.

Clove and allspice have often been reported to provoke allergic patch-test reactions in patients allergic to balsam of Peru. This is theorised to be as a result of these spices containing several of the same or related substances, e.g. cinnamic aldehyde, eugenol and vanillin.

Clove Allergy Test: Clinical Experience

Anecdotal evidence suggests that clove may induce symptoms of food allergy in sensitised individuals; however, few studies have been reported to date. It is possible that the allergy occurs more frequently than has been reported.

In a study of Type VI delayed-hypersensitivity reactions to spice, clove caused the most reactions, followed by Jamaica pepper and cinnamon.

In another study of 1,000 patients investigated for occupational skin disease, 5 displayed occupational allergic contact dermatitis (to the hand or finger) from spices. The causative spices were garlic, cinnamon, ginger, allspice and clove.

Oral irritation, purpura of the lips and stomatitis with clove oil have been reported.

Other reactions

Clove, present in a herbal product, has been said to potentially increase the risk of bleeding or potentiate the effects of warfarin therapy.

Health effects, including severe pulmonary toxicity, are suspected to be associated with clove cigarette (kretek) use among adolescents and young adults.