Prevalence and diagnosis of occupational allergy and its therapeutic considerations

By Anamika Chaudhary on April 13, 2017

Occupational allergy is an allergic reaction caused when exposed to an allergenic substance found at the workplace. This can be both indoor or outdoor. It is an important public health issue due to its high prevalence and socio-economic burden. It contributes significantly to the global burden of Asthma. Similarly, among other diseases like; rhinitis, eczema, skin diseases and conjunctivitis can also increase due to this allergy.

occupational allergy high for metal related work
Distribution of occupational allergic contact dermatitis cases reported

The main disadvantage with occupational allergy is that it remains undetected by both patients and physicians. Mainly the person who works in coal, asbestos, talc industry, soapstone mining, cosmetic industry suffer from occupational asthma. The main causative agents’ in the person who suffers from occupational dermatitis are antibiotics, preservative agents, detergents, cement, metal salts, alkalies, latex, and ionizing radiations (Pawankar, Holgate, Canonica, & Lockey, 2011).

Prevalence of occupational allergy

Allergic diseases at work can lead to two types of diseases. Firstly respiratory tract diseases (asthma and rhinitis) and secondly skin diseases (urticaria and eczema). In terms of respiratory tract disease, occupational asthma and rhinitis have a high global prevalence of nearly 15%. The main cause behind this allergy is high molecular weight proteins. Further, skin related allergies account for 8-34% of the occupational diseases. The main occupations which face the risk of occupation allergy include farming, painting, cleaning, spray painters, mine workers, laboratory researchers etc.

There is a different percentage for the prevalence of allergy in the US. However, with precaution, the percentage has decreased by 5.5% every year. Despite the declining trend, it is around 10%. A similar trend is observed in parts of UK as well, where an emphasis is not given to ensure that employees are not exposed to allergens. Overall, 9-20% of the population in the UK is suffering from some kind of occupation allergy. Although the maximum percentage is contributed by Asthma (Greiner, Hellings, Rotiroti, & Scadding, 2011; Kurt et al., 2009). Due to strict safety guidelines in Australia, the trend has declined by 50% in the last decade. The allergies which most commonly affect the population is asthma and dermatitis (Schoenwetter, Dupclay, Appajosyula, & Botteman, 2004). In the case of Japan, occupational asthma affects 9-15% of the population. This is also the most common disease affecting them (Dobashi, 2012).

Increasing occupational allergy in developing countries

With respect to Africa, currently, the prevalence is around 45-59%. An upward trend is observed affecting 49.7 million children below 15 years of age and 102.9 million adults below 45 years of age (Stanciole, Ortegón, Chisholm, & Lauer, 2012).  With respect to India, Asthma and contact dermatitis are the two most common allergic reaction affecting 5-10% of the population who deal with resin, epoxy, cobalt and nickel (Sarma, 2009). This clearly indicates that it is more prevalent in developing countries mainly because of obsolete technologies.

Diagnosis of occupational allergy

The symptoms of the disease are mostly work-related which reoccur again and again after re-exposure with the allergen. Diagnosis of occupational allergy is made usually in 2-4 years of onset of symptoms. Occupational allergy diagnosis depends on the acquired allergen. The diagnosis can be divided into in-vivo (epicutaneous skin prick test) and in-vitro test (RAST or ELISA) for detection of IgE specific allergen (Kelly, Wang, Klancnik, & Petsonk, 2011). In cases of skin-related allergies, the Patch test is done based on the allergen (oils, bakery items, preservatives, metal workers etc) (Zhao & Shusterman, 2012). Furthermore, immunological methods are generally useful for the diagnosis and quantification of allergen.

Therapeutic considerations

There is no evidence of whether occupational allergic population takes similar treatment to non-occupational diseases. Although, complete avoidance of exposure to the allergen decreases the severity of the disease. Using corticosteroids has been found to improve the symptoms of respiration-related allergens. Furthermore, pretreatment is necessary at the workplace or the workers are allergic to some substance (Cohn, Bahna, Wallace, Goldstein, & Hamilton, 2006; Sánchez-Borges et al., 2012).

Occupational allergy more costly than others

The financial burden of occupational allergy is more than the allergies caused due to genetic reasons. Occupational allergies affect more than 15% of the world population adding to the overall socio-economic burden. However, occupational allergy is preventable mainly if early diagnosis of the triggering agent is detected. Thus, standardized diagnostic procedures should be developed for both respiratory and skin-related occupational allergies. Further, the impact of environmental interventions should be assessed in order to develop cost-effective diagnostic and treatment strategies.