I- Definition :
Occupational skin diseases are skin conditions whose & rsquo; emergence and development are work related.
This definition includes in two distinct categories of dermatoses :
1- Dermatoses d & rsquo; only occupational :
Including the causal link is established between the & rsquo; appearance and & rsquo; dermatitis and worsening working conditions : If dermatitis d & rsquo; irritant solvents and cases of allergic contact eczema (Cement eczema).
2- Skin diseases aggravated by & rsquo; professional activity :
These are endogenous disorders can manifest clinically in certain occupations or aggravated by work : cases of psoriasis of the hands due to repetitive strain or even repeated mechanical friction (drilling and sanding) and if the & rsquo; atopic hand eczema or dyshidroses which is exacerbated by the wet work or in contact & rsquo; irritants (soluble oils).
II- L & rsquo; importance of occupational medicine dermatoses :
- Dermatoses represent 50 at 70% occupational diseases,
- More than 10% skin diseases,
- 1 at 2% current employees,
- Causes of & rsquo; increase in & rsquo; incidence of occupational skin diseases in recent years :
– industrial and food developments,
– New materials and chemical products,
– Inadequate training in & rsquo; hygiene and prevention,
– inappropriate use of cleaning products and skin protection.
- Occupational skin diseases : représentent 90%de dermites de contact dont 80% reach the hands and 10% to make,
- 80% and irritative 20% allergic,
III- Classification :
Once the RFP were classified into two types (classification de Sezary) :
- DP orthoallergic : observed identically, in all subjects exposed under the same conditions the same agents,
- Allergic DP : dependent d & rsquo; an allergic reaction.
Currently the DP are classified according to the causative factors :
- Infectious skin diseases caused by bacterial agents, mycological viral or parasitic (intertrigo, onyxis, folliculites suppuratives, herpes circiné…),
- Dermatoses caused by physical agents : vibrations, ionizing radiation, UV, microtraumatisme…),
- Dermatitis due to chemical agents : burns, dermatitis d & rsquo; irritation, dermatitis d & rsquo; wear, pigeonneaux.
IV- Diagnosis in the workplace :
A- anamnesis :
must specify :
- Dermatological and history & rsquo; atopy,
- Start d & rsquo; emergence of dermatosis : dates from the beginning of & rsquo; professional activity :
– Before or after the & rsquo; professional activity ?
– Subsequent to a change in chemical ?
- The chronology of & rsquo; lesional appearance rhythmic or not work : c & rsquo; is to say remission during holidays and weekends and reappearance to resume work,
- The original topography of lesions : linked or not to contact with the product (The hand is gripping a topography towards a product handled by the patient), example : reaching the dorsal hands for contact dermatitis),
- Coexistence at d & rsquo; s other workers & rsquo; business : that evokes the collective nature(for d & rsquo; d & rsquo dermatitis, irritation),
- L & rsquo; etiology is more difficult, we must find the & rsquo; irritant or & rsquo; allergen.
B- professional survey :
The approach is as follows through the & rsquo; professional investigation :
- O & rsquo; cleave to search with the patient various products to incriminate to d & rsquo; orient & rsquo; next step,
- Patch tests that will confirm or & rsquo; reverse the & rsquo; initial hypothesis,
- Detailing the & rsquo; work and professional gesture namely specify the type of products handled (label safety data sheets),
- Occasionally or daily, whether the & rsquo; burst coincides with a method of changing manufacturing,
- Specify the means of protection :
– What matters are the gloves you wear ?
– Which hand cleaning products do you use ?
– What protection do you use creams ?
- Sometimes the company doctor will get to visit the workplaces performed a post study,
- Try d & rsquo; establish a clear link between the professional actions and topography of lesions (example: eczema nickel scissors by hairdressers),
- Conduct a survey of sources Extra Professional : DIY, gardening, vehicle maintenance, cosmetic products, parfums, topical and local treatments.
C- Physical examination :
It is capital & rsquo; examine all the seed coat with search & rsquo; other locations :
1- Dermites irritatives de contact :
- Do not depend on immunological factors, due to the & rsquo; single or repeated application of & rsquo; chemical irritants,
- They appear in the first few hours after contact,
- Occur for all subjects exposed to & rsquo; irritant with a collective character,
- Clinique : the lesion is in the form of :
– Xerosis with fine desquamation and disappearance of fingerprints in case of & rsquo; fingers reached,
– Often a reaction hyperkeratosis,
– sometimes deep and painful cracks that become secondarily infected.
- Itching unimportant,
- No remote lesions : restricted to the area of contact with the & rsquo; causative agent,
- Lesions disappear 3 at 4 days after termination of the & rsquo; exposure,
- Patch tests are negative.
2- allergic contact dermatitis :
- It is in the & rsquo; application to the skin of & rsquo; an exogenous substance (hapten) triggering a reaction & rsquo; DTH cell-mediated Type IV al and Coombs taking place in two phases :
– First sensitization phase : beginner in the & rsquo; epidermis remains 4 at 7 days to go to completion,
– Second reintroduction phase : when the skin is again exposed to the same allergen then the & rsquo; eczema appear quickly 24 at 48 hours.
- L & rsquo; professional eczema may be more often based on products handled in the hands of the tips, of the fingertips and palms,
- L & rsquo; eczema to the peculiarity of s & rsquo; extend beyond the contact area or even cause remote injuries :
– Airborne (volatiles),
– Manuportés (dirty hands touching the face and thighs).
- Clinique : l & rsquo; eruption of & rsquo; eczema evolves into four phases
– Erythème prurigineux,
– Appearance associated vesicles or without edema or bubbles,
– Regression with scabs and peeling.
- The limits are generally poorly defined, crumbled or & rsquo; we do not always see blisters but often microérosions post vesicular,
- L & rsquo; chronic eczema : is drier and formed :
– Cupboards erythematous scaly ill-defined, prurigineux,
– Secondary infections may develop, s & rsquo; impétiginiser appearance with thick yellow crusts associated with fever and painful glands.
- Anapath : spngiose, exocytosis and dermal edema.
Elements differential diagnosis between eczema and contact dermatitis d & rsquo; irritation
|distinctness||Dermatose d’irritation||allergic dermatitis|
|Time d & rsquo; appearance||Fast (minutes or hours) after exposure||24 at 48 hours after a
|clinical appearance||Erythematous scaly lesions,hyperkeratotic Fissured (dry eczema)||vesicular lesions often congestive (wet eczema)|
|Limits damage||The net contact area||Overflows the region of contact with edges crumbled|
|eruptions seconds||missing||sometimes these|
|histology||Necroses keratinocytaires Reactions inflammatoires discrete||Spongiose- exocytose|
|Tests epicutanés||negatives||Positive and relevant to clinical|
V- exposed occupations :
Professional sectors with more health risk
- building industry and public works :
– Ciments (chromate et cobalt),
– Paint and varnish (epoxy resin, acrylates, polyurethane).
- Health sector :
– Rubber gloves (latex),
- hairdressing industry :
– permanent Products,
– locks Products (persulfates),
– metal Tools (nickel).
- mechanical industry :
– Components cutting oils,
– Metals and metal dust.
- d & rsquo sector maintenance and kitchen staff :
– Rubber gloves,
– Hand antiseptics,
– surface disinfectants.
WE- Explorations of Allergy & rsquo; contact dermatitis :
The diagnosis of & rsquo; allergic contact dermatitis is confirmed by skin tests :
– For medical care
– For further management in occupational disease (the practice of skin tests to & rsquo; occupational allergen is one of the essential elements)
– initial pass through rigorous approach to research & rsquo; identification of substances in the workplace
- Precautions for the patch test :
– The test site must be free from any skin disease,
– The tests must be made at least two weeks after complete healing skin test site
– The tests must be kept in place for at least 48 h,
– During the period of laying and reading tests, should neither wet nor take off so do not bath or sport and avoid skin trauma : transpiration, friction and pressure,
– No topical steroids on the test site for at least 1 week, no corticosteroids or & rsquo; immunosuppressive systemically since 1 month,
– Antihistamines do not alter skin reactivity to the patch test,
– The technique : includes & rsquo; application of the product diluted in a neutral non-allergenic substance (acetone or vaseline) on pellets which are fixed on the dorsal skin by a hypoallergenic, adhesive tape and are left in situ during 48 h.
– Reading : is in its Tissue 48 h and up & rsquo; to 96 h, 30 minutes after the & rsquo; removal of equipment to enable the & rsquo; attenuation of & rsquo; pressure effect of generating false negatives,
– There is a standard battery with twenty & rsquo; allergen most frequently responsible & rsquo; allergy and specific batteries or to professions (hair battery) or a group of products (battery adhesives, plastics),
– Interpretation : Score International Contact Dermatis Research Group (ICDRG) used each reading tests épicutaés.
|NT||not tested||Used to quote a missing allergen in a series|
|+ ?||doubtful||Erythème simple|
|+||weak positive reaction||Erythema and edema|
|++||Strongly Positive Reaction||Erythema, edema and bladder visible|
|+++||violently Positive reaction||Erythema, edema and bladder or coalescent bubbles|
|AND||d & rsquo reaction, irritation||missing edema, aspect fripé|
- Other skin tests :
– open test (open test) : the product is applied to the skin of the face of the bending & rsquo; forearm without occlusion, after checking the PH. useful for testing of professional products the & rsquo; irritant effect is unknown,
– Test semi open : same as the previous but this one is covered after 20 minutes. Useful pure test products whose composition is unknown (gangs, painting, resins…),
– Prick test : the skin is pierced by a lancet and a drop of & rsquo; allergen is deposited on the skin, reading is done after 20 .utile minutes to test & rsquo; hives and contact dermatitis.
VII- Prevention :
A- technical prevention :
1- collective prevention :
- Reduce worker contact with irritants or allergens,
- Substitute or replace certain chemical molecules,
- Employ closed process,
- Automation of certain operations,
- Advocating good ventilation and good local exhaust,
- Multiply visits and post studies to & rsquo; identify gestures and hazardous substances.
2- individual prevention :
Learning the correct professional actions :
- Avoid rinsing hands in solvents common case in garage,
- Avoid constantly dip their hands in caustic (detergents),
- Encourage hand washing near the work spot,
- Moisturize and soften hands after working with protective creams.
B- medical prevention :
1- Visit hiring : we depart subjects with a history of atopic dermatitis exposing positions in contact with substances known for their allergenicity but also irritating because of the skin's vulnerability.
2- periodic inspection : The occupational physician should look for signs of & rsquo; skin intolerance, mucous, respiratory or general to decide d & rsquo; a possible spreading of dangerous post.
Ensure regular monitoring of the dermatitis.
VIII- Repair :
The compensation of occupational dermatitis is achieved by & rsquo; d & rsquo intermediate; about 30 tables of professional diseases :
– Table number 64 : eczema lesions allergic mechanism,
– Table number 41 : occupational diseases caused by penicillins and cephalosporins and their salts,
– Table number 47 : occupational diseases caused by wood.
Cours du Dr Guennoun. – Faculty of Constantine