Occupational contact dermatitis

The dermatologist should be aware of the many facets of occupational skin diseases, which can be caused by physical, chemical, and biological insults. The most common manifestation of occupational skin diseases is contact dermatitis (both irritant and allergic). Three factors point out the importance of occupational skin diseases as diseases that have a public health impact: 1) occupational skin diseases are common; 2) they often have a poor prognosis; and 3) they result in a noteworthy economic impact for society and for an individual. They are also diseases amenable to public health interventions. Specific industries and exposures may put a worker at risk of occupational contact dermatitis. The accuracy of the diagnosis of occupational contact dermatitis is related to the skill level, experience, and knowledge of the medical professional who makes the diagnosis and confirms the relationship with a workplace exposure. Prevention of occupational contact dermatitis is important, and a variety of prevention strategies are available.     

Persistent post-occupational dermatitis

Wall and Gebauer (Contact Dermatitis 1991: 24: 241-243) first described persistent post-occupational dermatitis (PPOD) as ongoing dermatitis for which there is no obvious present cause, precipitated by prior occupational contact dermatitis (OCD). We propose that individuals exhibiting PPOD lose the capacity for resolution of their condition upon removal from exposure to causative agents and subsequently develop persistent dermatitis, which can be continual or intermittent. Accordingly, we suggest modification of criterion 6 of the OCD criteria developed by Mathias (J Am Acad Dermatol 1989: 20: 842-848): 'Removal from exposure initially leads to improvement of dermatitis, however, over time there may be incomplete or no improvement, despite removal from exposures at work'. To satisfy the definition of PPOD, individuals must meet at least 4 of the 7 criteria, including the altered criterion 6. We present 6 cases of PPOD exemplifying these scenarios, which met the altered Mathias criteria. In some cases, subsequent failure to recognize the initial work relatedness of their skin conditions resulted in the termination of workers' compensation benefits. This situation is particularly relevant in the Australian context. The diagnosis of PPOD needs to be considered in all individuals with work-initiated dermatitis who present with ongoing endogenous-like eczema.     

Venison contact dermatitis

A 37-year-old meat inspector presented with a 5-month history of forearm eczema. His symptoms improved at weekends and over holidays but flared within a day of work. Scratch patch tests were strongly positive to fresh venison diaphragm and venison liver and weakly positive to venison hide and blood, and lamb blood. They were negative to other venison and lamb components. Type IV allergy tests with Standard European and fragrance batteries were negative. The eczema cleared with a change in work role, clobetasol-17-propionate cream, flucloxacillin and aqueous cream. He was then able to return to meat inspecting. Provided he was diligent about applying 'Dermashield' barrier foam and minimizing contact with irritants, his eczema has remained well controlled over the last 4 years. Attention to irritant contact dermatitis is important in the management of protein contact urticaria.     

Contact dermatitis from a presumed allergy to paraphenylenediamine

Paraphenylenediamine (PPD) is a potent skin allergen found in permanent hair dye and temporary henna tattoo ink. Several cases of adverse skin reactions to PPD have been reported in the literature. Here we present a case involving a patient who acquired a temporary tattoo while vacationing in Mexico and subsequently developed contact dermatitis at the tattoo site. He provided a history of permanent hair dye use in the past with associated cutaneous reaction. Temporary tattoos have become increasingly popular with travelers and as a result so have reports of associated allergic contact dermatitis. Of concern is cross‐reaction of PPD to related compounds, severe reactions in younger populations and sequelae including increased sensitization, permanent scarring, and persistent postinflammatory hyperpigmentation.     

Nickel-elicited systemic contact dermatitis

20 patients with systemic contact dermatitis due to nickel are described. Of these patients, 15 were female and 5 were male. Their mean age was 24.8 years (16-51 years). All had experienced contact dermatitis in the umbilical area due to continual contact with metal belt-buckles or buttons. Then, with long- or short-term aggravation of such periumbilical dermatitis, commonly in summer, lesions spread to other sites such as the side of the neck, the flexures of the extremities, etc. All patients showed a positive patch test to nickel sulphate (2.5% in petrolatum) and the dimethylglyoxime test demonstrated the presence of free nickel on metal buttons or belt-buckles. Punch biopsies performed in 7 patients showed subacute dermatitis. After avoidance of continual exposure to objects containing nickel and foods rich in nickel, as well as treatment with oral antihistamines and topical corticosteroids, all patients improved or cleared. It has been reported that nickel can cause systemic contact dermatitis by some internal systemic route, such as oral intake, transfusion, inhalation, implantation of metal medical devices, etc. In our patients, we found that continual local skin contact could also elicit systemic contact dermatitis.     

Allergic contact dermatitis in children

INTRODUCTION: Allergic contact dermatitis (ACD) is equally as likely in infancy as in adulthood, and represents 20% of all cases of dermatitis in children. Its true prevalence and incidence are, however, unknown. MATERIALS AND METHODS: We have conducted a retrospective study over 10 years of a group of patients aged 15 years or less, with clinical suspicion of ACD. Patch tests were performed in accordance with the standards of the GEIDC. RESULTS: The study covered 96 patients with a mean age of 10.57+/-0.67 years. The zones most frequently affected by eczemas were those of diffuse distribution (28% of patients) and of the hands (27%). We found at least one positive response in 52% of the cases. The most frequent allergens were thiomersal (21%), mercury (19%) and nickel (18%). We have found a statistically significant association between age of less than 15 years and positive response to thiomersal [P<0.01; OR: 8.5 with confidence interval (CI) 95%: 5.08相似文献   

The immunology of Contact dermatitis

This review summarizes current knowledge of the pathophysiological events which lie behind the development of contact dermatitis. The clinical distinction between allergic and irritant eczema is discussed. New observations are evaluated on our understanding of how allergic and irritant eczema may in many respects be similar, evolving through common physiological pathways of immune inflammation.     

Sites of dermatitis in a patch test population: hand dermatitis is associated with polysensitization

Background  Sites of dermatitis in larger series of contact allergic patients are rarely reported. Increased risk of polysensitization has been linked only to stasis dermatitis and leg ulcers. However, a large proportion of polysensitized individuals may have dermatitis in other skin areas.
Objectives  To examine the site of dermatitis at time of first appearance in contact allergic individuals with special focus on the distribution of dermatitis in polysensitized individuals and to examine if widespread dermatitis is more frequent in polysensitized than in single/double-sensitized patients.
Methods  A matched case–control study was carried out including 394 polysensitized and 726 single/double-sensitized patients who responded to a postal questionnaire. All subjects were recruited from a hospital patch test population.
Results  The hands were the most frequent and the anogenital region was the least frequent skin area affected with dermatitis. Dermatitis on the hands/wrists [odds ratio (OR) 1·58], in the armpits (OR 1·56) and on the back (OR 1·91) was positively associated with polysensitization. The hands were the only skin area with dermatitis which maintained the association to polysensitization in two subpopulations consisting of, respectively, individuals with and without atopic eczema. Dermatitis on the scalp was negatively associated with polysensitization (OR 0·66) primarily for individuals without atopic eczema. The dermatitis did not seem to be more widespread in polysensitized compared with single/double-sensitized patients.
Conclusions  Special awareness in patients with hand dermatitis seems justified either to prevent development of multiple contact allergies or to document polysensitization as an aetiological factor.     

Occupational dermatitis in bakers: a clue for atopic contact dermatitis

6 patients are described who developed contact dermatitis after cereal contact on atopic skin for periods of 2 to 20 years. 2 patients were wheat flour patch-test-positive. They had punch biopsies taken for standard histological and immunohistochemical investigation by labeling with monoclonal antibodies, anti-DR and anti-IgE. Sections showed features of contact dermatitis. There were many dendritic cells located perivascularly in the papilla and in the epidermidis, intensely positive for monoclonal anti-IgE antibody. In control atopic subjects, there were a few perivascular IgE positive cells, probably mastocytes. This study shows that there may be a relationship between some allergens and atopic eczema in patients exposed to them in the course of their work. In some cases, there was a true allergic contact dermatitis, seen through the clinical and histological characteristics, and the results of immunohistochemical study.     

Allergic and photoallergic contact dermatitis to chlorpromazine

Chlorpromazine is known to produce both systemic phototoxic and photoallergic reactions. However, it may also cause photoallergic contact dermatitis and, albeit exceptionally, allergic contact dermatitis (ACD). We present a series of photoallergic contact dermatitis and ACD to chlorpromazine diagnosed at a tertiary centre cutaneous allergy unit between 1980 and 2019.     

Contact dermatitis to training toilet seat (potty seat dermatitis)

Allergic contact dermatitis from various components of toilet seats has been well described. We report a case of a young boy presenting with an atypical pattern of dermatitis who was found to be allergic to his training toilet seat. This case highlights the importance of recognizing this diagnosis and the role of potty seats as the causative factor.     

Contact dermatitis to Asparagus officinalis

A 53-year-old farm worker presented with a 3-year history of an occupational allergic contact dermatitis to asparagus. The dermatitis cleared quickly with courses of systemic corticosteroids but relapsed within days of further exposure to asparagus. The genera Asparagus is made up of some 300 species. It belongs to the family Liliaceae which includes tulips, onions and garlic. Asparagus contains asparagin, coniferin and the glucoside vanillin. The allergen may be a plant growth inhibitor, 1,2,3-Trithiane-5-carboxylic acid, which is present in young shoots.     

Contact dermatitis of the vulva

Contact dermatitis of the vulva is common, with irritant contact dermatitis occurring more frequently than allergic contact dermatitis. Patients with chronic vulvar dermatoses are at greater risk and should continually be reassessed for possible contact dermatitis. Comprehensive and specific questioning about hygiene practices and product use is necessary to elicit a history of contactant use. Patch testing is required to identify relevant contact allergens, the most common of which include medicaments, preservatives, and fragrances. Patient education and follow-up are essential in optimizing treatment and preventing recurrence of vulvar contact dermatitis.     

Allergic contact dermatitis from cardamom

A case is presented of a confectioner with a chronic hand dermatitis and positive patch test reactions to cardamom and certain terpenoid compounds present in the dried ripe seeds of cardamom. Cardamom is a popular traditional flavouring agent for baked goods and confectionery. Dermatitis from skin exposure to cardamom has to the best of our knowledge not been reported. We report one case of allergic contact dermatitis to cardamom elicited by terpenes present in the seeds.