Occupational skin disease in Singapore and the Covid-19 pandemic
Dr. Suzanne Cheng
Chief of Contact Dermatitis Unit, National Skin Centre Singapore
Occupational skin disease (OSD) is more common than we think! Defined as a skin condition contracted due to exposure to risk factors at work, OSD is the third leading cause of occupational diseases in Singapore, following noise-induced deafness and musculoskeletal disorders.
Occupational skin disease is preventable. All we need to do is recognise OSD early, institute appropriate interventions and implement preventative measures in the workplace. Doing so enables affected individuals to return to work and remain employable.
The JODC process. To manage and prevent OSD efficiently, the Joint Occupational Dermatosis Clinic (JODC) was established in 1982. The clinic operates monthly and is staffed by dermatologists from the National Skin Centre and occupational medicine physicians from the Ministry of Manpower (MOM). Three consecutive visits over a week are required, typically on Friday, the following Monday, and Friday. On the first visit, patients undergo a thorough interview. Most patients present with hand eczema and report frequent contact with chemicals and wet work. Patch testing to commercial allergens and the patient’s own items is conducted to differentiate between irritant and allergic contact dermatitis. Day 3 and Day 7 readings are performed on the second and third visits. If the presenting dermatosis is contact urticaria, skin prick tests are performed.
One limitation of patch testing is the inability to test for caustic, toxic, and carcinogenic workplace chemicals. Therefore, examining the safety data sheet for each chemical provided by the patient is crucial.
Diagnosing OSD and reporting requirements. On the third JODC visit, a conclusion is made regarding whether the case is a work-related skin disease. OSD is notifiable under the Workplace Safety and Health (WSH) Act. Both the diagnosing physician and the employer are obligated to report confirmed cases of OSD on the “WSH Incident Reporting” website. Cases deemed work-related qualify for work injury compensation under the Workplace Injury Compensation Act (WICA).
If patch tests are negative and a work-related skin disease is strongly suspected, particularly when other co-workers are similarly affected, a workplace visit may be arranged. Those interested should watch for our upcoming poster entitled “Fibreglass dermatitis – Diagnostic challenges and occupational interventions” during the Congress. Our workplace visit played a vital role in treating the patient and improving the working conditions of his co-workers.
Our JODC experience. Our 10-year data from 2009-2018 (Kho et al. Contact Dermatitis. 2020; 83:531–533) revealed that out of 526 patients patch tested, 256 patients were diagnosed with OSD. Hands were involved in 80% of cases, and 87% presented with eczema. Irritant contact dermatitis accounted for 55.3% of cases, 43.1% were allergic contact dermatitis and 1.5% were contact urticaria. The most common irritants were wet work/detergents, followed by greases/oils and occlusion. The most prevalent allergens were chromate, resins, and rubber chemicals. The prevalence of atopy in patients with OSD (34.8%) was higher than the general population.
The incidence of OSDs at our centre has declined from 262.5 cases/year (1984-1985) to 26.4 cases/year (2009-2018). Reasons for the decline include enhanced workplace safety and health regulations, decline in GDP in goods-producing sectors where most OSD patients were employed and a successful JODC service.
Problems faced during Covid-19 lockdown: The JODC faced a temporary suspension of services in 2020-2021 due to Covid restrictions. As a result, a backlog of cases accumulated. To address this issue, the JODC conducted remote sessions via Zoom, with patients attending the National Skin Centre in person and MOM physicians providing expertise remotely. Physical JODC operations resumed in January 2022.
Key challenges in OSD management: Preventing and treating hand dermatitis in healthcare workers (HCWs) has always been a major challenge. This issue has been exacerbated by the Covid-19 pandemic, which has emphasized the importance of proper hand hygiene. HCWs worldwide have struggled with irritant hand dermatitis due to frequent hand washing, antiseptic use (e.g., chlorhexidine, povidone iodine), alcohol-based handrub solution (ABHRS) use, and prolonged glove use. To mitigate the adverse effects of frequent hand washing and sanitising, emollients such as glycerol, dexpanthenol, levomenol, myristyl alcohol, and lanolin are now added to ABHRS.
In some cases, HCWs may develop a true contact allergy, commonly to rubber accelerators in gloves. These individuals often suspect their allergy and report improvement in their symptoms when off work and when using alternative gloves (most commonly by wearing a layer of polyethene gloves or vinyl gloves under their rubber gloves). Patch testing can confirm the allergy, enabling employers to provide suitable gloves and the affected individual to claim work injury compensation. Ideally, the affected HCW could change their job scope or profession, but this is often easier said than done.
Chlorhexidine, a commonly used antiseptic in handwashes and ABHRS, may cause skin irritation or, in rare cases, allergic contact dermatitis. Although patch testing to ABHRS is not possible due to its volatility, we can test for potential allergies using commercial chlorhexidine digluconate and chlorhexidine diacetate allergen.
Our role as dermatologists. Dermatologists and Designated Workplace Doctors (DWDs) play a crucial role in confirming and notifying OSD cases. If there is any doubt, suspected OSD cases should be referred to the JODC at the National Skin Centre or another Occupational Health specialist clinic. This will help determine the work-relatedness of the condition and the individual’s eligibility for claims under the Work Injury Compensation Act (WICA).