professional dermatoses

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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,
– Suintement,
– 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

sensitization

prior

Frequency collective individual
sYMPTOMS

subjective

burns pruritus
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 :

– disinfectants,
– detergents,
– Rubber gloves (latex),
– pharmaceuticals.

  • hairdressing industry :

– Colorants,
– 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.

Score Interpretation elementary lesions
NT not tested Used to quote a missing allergen in a series
Negative Unresponsive
+ ? 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