Occupational Allergy
Exposure to allergens or chemicals while “on the job” can cause occupational allergies such as asthma, rhinitis, conjunctivitis, urticaria and contact dermatitis. Some substances like latex may cause both respiratory and skin allergies.
Asthma is characterized by intermittent respiratory symptoms; i.e., chest tightness, wheezing, cough and shortness of breath. 10-25% of cases of adult asthma are attributable to occupational factors. We can estimate that in Europe there are 1/2-1 million workers with occupational asthma. The main occupations at risk of occupational asthma are bakers, laboratory animal and health care workers, spray painters, cleaners, woodworkers, farmers and hairdressers.
Rhinitis is characterized by nasal blockage, sneezing, running and itchy nose. Occupational rhinitis is three times more frequent than occupational asthma and it is often associated with occupational conjunctivitis (itching, tearing, irritation and redness of the eyes). The agents responsible for occupational asthma and rhinitis are the same, and a majority of patients diagnosed with occupational asthma also suffer from occupational rhinitis, which usually precedes the onset of occupational asthma.
Occupational dermatitis is one of the most common causes of occupational disease and accounts for many workdays lost. Symptoms of acute occupational dermatitis are red, swollen and itchy skin. In the chronic stage the skin shows vesiculation, oozing, desquamation and fissures.
Main occupations at risk include builders, florists, nurses, hairdressers and printers.
Natural rubber latex is used to make latex gloves, condoms, balloons, rubber bands, erasers and toys. Latex allergy became frequent in the late 1980’s when health care workers started using powdered latex gloves to prevent infections such as hepatitis and AIDS. In the last 15 years the increased use of non-latex or powder-free gloves determined a decline in latex allergy. Latex allergy may manifest with contact urticaria, rhinitis, conjunctivitis, asthma and contact dermatitis.
Diagnosis
Diagnosing occupational asthma: the first step is clinical and occupational history which allows to consider the possibility of the disease and its relationship to work. Once occupational asthma is suspected, objective tests such as pulmonary function and skin or blood allergy testing are very useful to confirm the diagnosis. The best available means to give a convincing demonstration that asthma is caused by an occupational agent is the controlled exposure to the agent (specific inhalation challenge) in a laboratory in a specialized centre.
Diagnosing occupational rhinitis: similar to occupational asthma, it is based on clinical and occupational history and on skin or blood allergy testing. In some cases a specific inhalation challenge may be performed, as described above.
Diagnosing occupational dermatitis: it is based on clinical and occupational history, physical examination and skin allergy testing (patch testing).
Diagnosing occupational latex allergy: it is based on clinical and occupational history, skin or blood allergy testing and respiratory function test in the case of respiratory symptoms.
Management
Managing occupational asthma: the best treatment is avoidance or minimization of exposure to the responsible agent, although often it is difficult for the patient to change his job without adverse socio-economic consequences such as income losses. Pharmacological treatment is the same as for subjects with asthma.
Managing occupational rhinitis: complete avoidance of causal exposure may induce adverse socioeconomic consequences, such as unemployment and income loss. Consequently, reduction of exposure, pharmacological treatment and close medical surveillance may be considered an acceptable approach.
Managing occupational dermatitis: it is based on strict avoidance of causative substances and local pharmacological treatment.
Managing occupational latex allergy: In the case of contact urticaria, it is usually effective for the patient to use powder-free latex gloves or non-latex gloves (vinyl or nitrile gloves). If the nose is involved, it is mandatory that all co-workers of the patient use powder-free latex gloves, as the lubricant powder releases latex particles in the work environment where latex allergens can be inhaled. In the case of asthma and contact dermatitis, a complete avoidance of latex gloves and other latex products is suggested.
Coping
As stated above, avoidance is the cornerstone in coping with occupational allergies. Sometimes it may be implemented avoiding the triggering substance, but this is not always possible. A second measure would be to implement personal or general protection with adequate facemasks, gloves, air filtering systems, etc.
Preventing occupational asthma and rhinitis: a close control of the airborne levels of the agents known as cause of occupational asthma (air monitoring) is the best way for prevention. Education of workers and, at an earlier level, of young adults entering the workforce about risks of occupational asthma is also important.
Preventing occupational dermatitis: substitution of responsible substances, modification of production processes to avoid skin contact with hazardous substances, information and training of workers and use of protective agents and gloves are the most effective preventive measures.
Preventing occupational latex allergy: the use of powder-free latex gloves, vinyl and nitrile gloves and the avoidance of other latex products is very effective in preventing occupational latex allergy.