Diagnosis and Confirmation
Occupational skin diseases include a spectrum of conditions which include irritant contact dermatitis; allergic contact dermatitis; skin cancers, infections, and injuries; amongst other skin diseases. ACD is one of the most commonly reported occupational skin diseases in Singapore and worldwide .
Given the non-specific pattern of hand dermatitis, it is often clinically difficult to differentiate between ACD and ICD. A detailed occupational and social history is required to identify the possible agent. The clues for ICD are that the rash occurs more subacutely and sometimes chronic after exposure. The rash is also more dramatic and the pain is more prominent than the itch. On the other hand, ACD tends to affect all exposed areas. In this case, the feet were spared. Hence, making the diagnosis of ACD less likely. ACD requires prior sensitisation before the presentation thus; the duration of rash from exposure may be variable. There is a more prominent itch in ACD as compared to the pain and the rash takes longer to resolve after onset . Other differential diagnoses to consider include photo-provocated dermatoses such as polymorphous light eruption, infections, or blistering dermatoses associated with autoimmune conditions. However, the history and physical examination excluded these differentials.
While a clinical diagnosis may suffice in most cases, a full evaluation with a patch test is still warranted, to confirm the diagnosis in the patient. It is important to understand if he was truly allergic to the butyl gloves or other allergens . The initial management was still critical, to eliminate exposure to the suspected offending agent to prevent recurrence of the rash. Butyl gloves are made of inert compounds, meant to act as protective barriers when handling hazardous material. However, there is the presence of rubber accelerators and compounds within the gloves during the manufacturing processes. Therefore, material data safety sheets are useful adjuncts for clinicians to make the correlation with the possible offending agent.
Long-term use of occlusive gloves has been reported to have a negative effect on skin barrier function, especially when the occlusion is extensive and combined with exposure to skin irritants such as soap and detergents . The occlusion results in moisture trapped in the skin, resulting in softer skin that is more sensitive to irritants . Hence, the cotton gloves served two functions. Firstly, it served as a barrier to prevent direct contact with the butyl gloves. Secondly, to soak up water and sweat that may accumulate in the thick non-absorbent butyl gloves to prevent ICD. This double glove technique, which includes a cotton liner, can prevent the development of the impaired skin barrier function that can be caused by prolonged wearing of occlusive gloves . Chemical additives in gloves, including rubber accelerators such as benzothiazoles and thiurams, may also contribute to skin irritation; and natural rubber latex gloves have been reported to cause occupational contact dermatitis and urticaria .
Fitness for work
In this instance, the specialist or occupational medicine officer did not require a workplace visit. This was because the unit MO had a good understanding of the exposure, temporal sequence of the rash, and can also recommend modifications in the training, schedule, rest days, reduce exposures. The MO also has direct access and contact with the unit superiors for communication. Moreover, in the military, if it was due to ACD to the protective gloves, the medical board can decide the suitability for continued deployment and fitness for return to work.
In addition to the above, education of the affected individual is equally important to prevent recurrences out of the workplaces. Therefore, patient information leaflets or online resources should be given to enhance understanding of common materials or products with the offending agent. The unit medical officer and patients’ direct superiors should also continue to monitor the individual for further recurrences, as ICD can recur in other similar settings.
Based on the hierarchy of controls by The National Institute for Occupational Safety and Health (NIOSH), different control measures can be utilised to eliminate foreseeable risk. In this case, substitution or change of personal protective equipment was not possible as the protective gloves were part of the requisite force protection posture for combat medics in this military environment. Moreover, there are no suitable alternatives in the logistics chain to replace the gloves. While engineering controls through using a “double-glove” method of donning a cotton glove before the protective glove was employed, this was not possible to eliminate using protective gloves. Administrative controls to change work processes or institute instructions to reduce exposure were deemed not satisfactory for PPE. Therefore, the decision for revocation or to change his work environment was deemed unnecessary.
Implementation and review
After the implementation of suitable control measures, regular reviews and surveillance must be conducted. The MO can also look out for trends of similar cases occurring within the unit or other units and to flag out possible alarming statistics early, to alert the authorities to review existing equipment. There was heightened awareness in this case due to the exposed individual being a healthcare worker and low barrier to access to a medical officer. However, there may be a lack of awareness of the possibility of occupational diseases in other vocations and/or units in the military. Hence, there remains a need to increase awareness of occupationally related diseases (including occupational dermatoses) in military commanders, as well as education of military medical officers to assess and look for occupational exposures. The unit should be vigilant to look out for similar conditions or introduce cotton gloves as a barrier function. This can be calibrated to at-risk personnel, especially those with a history of hand eczema, or a reported history of previous ICD of the hands. At the systems level, the military should reinforce and encourage open reporting of occupational disease.
A workplace registry is important to detect trends of occupational disease, as well as work-related illnesses. Also, a joint clinic by dermatologists and occupational medicine specialists may be useful to provide a holistic assessment of the patient; but this is only available in a tertiary dermatological referral centre. In terms of monitoring at the macroscopic level, it is important to amalgamate disease trends across other units within the military. This is important to decide if the systematic introduction of intervention and preventive measures is required for other troopers who train with protective gloves and equipment.
Learning points & Clinical relevance
While butyl gloves are mainly used in specialised areas within the military, the growing need for PPE usage in the COVID-19 pandemic necessitates increased awareness for contact dermatitis to PPE . There are increased numbers of healthcare workers, as well as ancillary personnel working in the frontline who are required to don PPE. This similar phenomenon was also observed in the SARS epidemic according to a local study at the National Skin Centre Singapore . Biosafety Level (BSL) 3 precautions are also undertaken when handling samples associated with COVID-19 to reduce the risk of infection in healthcare workers . This has led to the development of protective gloves used in biosafety cabinets for swabbing, which are made of heavy-duty rubber such as Neoprene .
In addition, it is important to recognise that latex or nitrile gloves used by healthcare workers may also result in contact dermatitis. There have been numerous studies showing glove ACD affecting healthcare workers due to their prolonged exposure with regular use [13, 14]. Rubber accelerators such as carbamates, thiurams, 2-mercaptobenzothiazole (MBT), and 1,3-diphenylguanidine (DPG) are a few of the common contact allergens identified to be responsible allergens amongst healthcare workers as well .