Allergic rhinitis and rhino-conjunctivitis (ARC)
Depending on the route of exposure, rye and wheat allergy may have different clinical manifestations including classical food allergy symptoms that affect the skin, gastrointestinal system, or respiratory tract; occupational rhinitis or asthma and contact dermatitis; and even exercise-induced anaphylaxis (5). Moreover, allergens in rye flour, similar to other cereals are resistant to gastrointestinal enzymes and can provoke a reaction upon ingestion (5).
A 38-year-old male baker presented with a two-month history of rhinitis, asthma, and urticaria on arms by exposure to rye flour. The patient showed heightened sensitivity to rye than to other cereals. Rye has been studied to elicit a more robust physiological bronchial response than other grains like wheat (21).
A 35-year-old man working in a bakery for seven years reported aggravation of allergic rhino-conjunctivitis (ARC) upon exposure to rye flour. A 32-year baker from Cuba complained of ARC on rye flour exposure in the bakery where he worked for three years (22).
A 32- year old male baker with a history of smoking and ARC in Japan presented aggravation of ARC, chest tightness, cough, and wheezing while handling rye flour (23).
In a study on rye allergy to woodworkers (since rye four is used in the wood industry), all nine subjects exposed to wood dust and having a history of occupational allergy showed a positive response to commercial rye flour extracts in skin prick and conjunctival tests (17).
Asthma
Inhalation of flour from rye, wheat, barley, soya bean, and buckwheat are reported to trigger respiratory allergic symptoms and asthma and among them, rye, wheat, or barley are mostly known to be responsible for these allergies (19)Allergens in rye flour are known to cause occupational asthma, particularly Baker’s asthma since rye flour is popularly being used to produce “special bread” (5, 16).
A 38-year old baker exhibited asthma and other respiratory symptoms on exposure to rye flour or mixes of rye flour only, and not any other cereal (21).
An old, asymptomatic baker who shifted to working from a bakery in Cuba to Spain complained of developing respiratory symptoms, including asthma, which aggravated with rye flour exposure. He reported severe and more frequent asthma attacks requiring immediate emergency hospital admission due to rye four allergy (22).
Food allergy syndrome and Anaphylaxis
Ingestion of rye can trigger food allergy symptoms in the gut and skin and may cause anaphylaxis (5). Anaphylaxis following the ingestion of rye has been documented. A case of a 61- year old woman without any history of drug allergy, suffering from rye-dependent exercise-induced anaphylaxis upon ingestion of toasted rye bread, has been reported. The woman developed generalized erythema, dizziness, hypotension,and facial angioedema after a 30-minute walk, one-hour post-ingestion of rye (24). A 32-year old Japanese baker with a history of ARC presented with anaphylactic symptoms including urticaria in the upper body, facial swelling, dyspnea, and angioedema on eyelids after consumption of bread containing 50% rye flour (23). Similarly, another study demonstrated a case of a 38-year old male baker with a history of urticaria on arms after exposure to rye flour (21).
Contact dermatitis
Flour-associated contact dermatitis is frequently reported in sensitized individuals. The most commonly responsible agents are wheat and rye. A woman with a history of atopic eczema on fingers since childhood reportedly developed itchy rashes on her hand upon handling a dough made of both wheat and rye and wet chapatis. Dry flour did not trigger any symptoms. Also, the patient did not develop symptoms of allergy or AR after eating cooked chapatis. She tested positive in SPTs for both wheat and rye individually and together (25).
