occupational skin diseases dr. alireza safaiyan occupational medicine specialist
TRANSCRIPT
Introduction
The second cause of occupational diseases ( 23-25% of all occ.diseases )
A skin disease that is caused by physical, biological or chemical factor in work
Also a worsening of pre-existing skin disease can be termed as occupational skin disease
Classifications of work-induced skin diseases
Occupational dermatitis Occupational photosensitivity reactions Occupational phototoxicity reaction Occupational skin cancers Occupational contact urticaria Occupational acne Occupational skin infections Occupational pigmentary disorders Miscellaneous
Diagnosis Of Occupational Skin Diseases
Patient history: Does skin disease relate to work?
Exposure: Are there causative agents (allergens, irritants) in the work-place?
Clinical symptoms: Are they in accordance to clinical disease?
Questions
When did disease start? In which skin area was the first
symptom? What is work technique? Free time, other works Cleaning measures Protection Vacation, holidays
Contact Dermatitis
Occupational dermatitis is an inflammation of the skin causing itching, pain, redness, swelling and small blisters.
Contact dermatitis is an eczematous eruption caused by external agents, which can be broadly divided into:
• Irritant substances that have a direct toxic effect on the skin (irritant contact dermatitis, ICD)
• Allergic chemicals where immune delayed hypersensitivity reactions occur (allergic contact
dermatitis, ACD).
What Types?
Irritant Contact
80% of all dermatitis is
caused by direct contact with a
substanceIt may occur
randomly
Allergic Contact
Once sensitised, the problem is life
long and any exposure to the substance will
result in an attack
What Causes it?
Irritants Detergents Solvents Engine oils Cutting fluid Lubricants Fibreglass
Allergens Salts Nickel Epoxy resins Dyes Rubber
Common site of involvement
Skin disease starts on the area of contact.
Dorsal aspects of hands and fingers, volar aspects of arms, interdigital webs, medial aspect of thighs, dorsal aspects of feet.
Prognosis Of Occupational Dermatitis After Treatment
25% complete recovery 25% refractory 50% remitting / relapsing
Acute ICD
• This is often the result of a single overwhelming exposure or a few brief exposures to strong irritants or caustic agents.
• Common work chemicals: – Concentrated acids (sulfuric, nitric, chromic,
hydrochloric, hydrofluoric acids)– Strong alkali(CaOH,NaOH,KOH),wet concrete,
sodium and potassium cyanide– Organic and inorganic salts, e.g. dichromates,
arsenic salts– Solvents/gases, e.g. acrylonitrile, ethylene oxide,
CS2
Clinical Presentation
Stinging, burning, painful, erythematous eruption occur after brief contact with strong irritant chemicals.
Erosion and skin ulceration may occur.
May result in permanent scar.
Chronic (cumulative) ICD
Repetitive exposure to weaker irritants -Wet : detergents, organic solvents, soaps,
weak acids, and alkalis -Dry : low humidity air, heat ,dusts , and
powders Disease of the stratum corneum Is due to a stepwise progression of damage
to the barrier function of the skin
Predisposing Factors
Endogenous factors:• Dryness vs wetness• Sweating• Age• Atopic predisposition• Hx of skin diseases
Causes of Chronic ICD
Water/wet work Detergents Antiseptics Disinfectants Soap/cleansing agents Weak Acids & alkali Wet cement Solvents Low humidity friction
Fiberglass fibers Cutting oil Food Pesticides Plants & vegetation Rubber products Acrylic resins Soldering flux Dusts Degreasing agents
35% Washing 10% Solvents 6% Plastics and
adhesives 6% Foodstuff 5% Dirty, wet work 5% Mineral oils
At risk occupations: Bartenders Caterers Cleaners Hairdressers Metalworkers Nurses Solderers Fisherman construction
workers.
Clinical Presentations
Usually presents with dry, scaly fissuring, lichenified and eczematous lesions on the fingers and hands.
Vesicular lesions do occur but are less common than in ACD.
May in face ( forehead, eyelids, ears, neck) and arms due to airborne irritant dusts and volatile irritant chemicals
Management
Removal from exposure in active lesion Treating the active case
• Topical corticosteroids• Soap substitutes• Emollients
Second line (for steroid resistant cases):
• Topical PUVA• Azathioprine• Cyclosporin
Allergic Contact Dermatitis
Caused by low-molecular weight haptens
Hapten is “incomplete allergen” Binds to carrier protein for
immunogenicity Low molecule weight enables
penetration of hapten
Occupational Skin Allergens
Poison oak/ivy Metals:
• Chromium• Nickel• Gold• Mercury• Cobalt
Rubber industry• Accelerators• Antioxidants
Plastic resins• Epoxy resins• PU resins• Phenolic resins• Formaldehyde resins• Acrylic resins
Rosin ( colophony )• Soft soldering
Organic dyes ( azo dyes ) Methyl metacrylate Plants Latex and its powder Germicides and biocides
• e.g. lanolin Some pesticides Some solvents
• Formaldehyde• Turpentine• Aliphatic amines
Nitrates Ethylene oxide
Clinical Features ( Acute Form )
Rash appears in areas exposed to the sensitizing agent, usually asymmetric or unilat.
Sensitizing agent on the hands or clothes is often transferred to other body parts.
The rash is characterized by erythema, vesicles and sever edema.
Pruritus is the overriding symp.
Clinical Features ( Chronic Form )
Thickened , fissured, lichenified skin with scaling
The most common sites:• Dorsal aspect of hands• Eyelids• periorbital
Patch Test
Confirm delayed hypersensitivity Material& technique:
• Medium• Adhesive• Marking of the test• Occlusion for 48 h• Read in after 72-96 h
Interpretation of patch test result
Nothing: negative reaction Erythema, papules, infiltration, no vesicle:
weak reaction Erythema, vesicular eruption, edema:
strong reaction Bulla, ulceration: extreme reaction
Erythema to eczematous: irritant reaction
•Doubtful reaction ( )?
Faint macular or homogeneous
Erythema, no infiltration
Weak positive reaction )+(
Erythema , InfiltrationDiscrete papules
•Strong positive reaction( )++
ErythemaInfiltration
PapulesDiscrete vesicles
•Extreme positive reaction( +++)
Coalescing vesicles/bullous reaction
Management & Prevention
Removal from exposure ( lifelong)
Drug treatment• Topical steroid• Emollients
Prevention• Like ICDs
Irritant versus Allergic dermatitis
ICD• Hx. Of contact with
known irritant• Acute onset• Stinging, Burning• Neg. patch test• Localized • Many people• Improved with long
vacation (3 weeks)
ACD• Hx. Of contact with
known allergen• Delay onset (1-3d)• Itching, Vesicle • Positive patch test• Spreads• Few people• May improved even on
weekends
Mathias criteria for occupational contact
dermatitis (4 of 7) Clinical appearance Workplace exposures Anatomic distribution Temporal relationship Non-occupational exposure Improvement Patch test
Contact photodermatitis
Some chemicals may cause CD only in the presence of light
Sunlight or artificial light sources that emit specific wavelengths
2 categories: -phototoxic -photoallergic
Phototoxic Photoallergic
Coal-tar derivative Dyes (Eosin) Drug -phenothiazines -sulfonamides Plants&derivative -psoralen -lemon
Antifungal agents Fragrances Halogenated
salicylanilide Phenothiazines Sunscreens Whiteners Agricultural
Clinical course
Phototoxcic: - painful , exaggerated sunburn that may
develop bullae and pigmentation -by avoiding the agent, dermatitis usually
disappears promptly Photo-ACD: - many of the features of ACD ( itching ,
vesiculation)
Where involved ?
Exposed areas: face, ant. V of the neck, back of the hand, uncovered sites on the arm&leg
Hairy areas, upper eyelids, and below the chin may be spared
Contact Urticaria
Immunologic :• Caused by proteins that act as allergens• Proteins penetrate through skin⇝bind to IgE
on the surface of mast cell⇝ release of histamine and other mediators (type-1 reaction)• Sometimes generalized reactions occur• Latex allergy
Contact Urticaria
Nonimmunologic:• Caused by chemicals• Direct pharmacologic action on skin
cells• No sensitization necessary• More common than suspected
Occupational Causes
Latex allergy ( m/c ) Formaldehyde Food industry
• Plants• Vegetables• Animal products
Pharmaceutical industry• Streptomycin
Clinical Features Of Contact Urticaria
Hives (edema) appear on sites of contact within minutes
The hives disappear within 1-4 hours
Mild: Only itching Severe: Systemic symptoms
(anaphylaxis)
Contact Urticaria
Nonimmunologic:• Caused by chemicals• Direct pharmacologic action on skin
cells• No sensitization necessary• More common than suspected
Occupational Skin Cancers
The second m/c form of occupational skin diseases
About 17% of all cases of occupational skin diseases
What Cancers?
Malignant lesions:
• Basal cell carcinoma
• Squamous cell carcinoma
• Malignant melanoma
Pre-malignant lesions:
• Actinic (solar) keratoses
• Tar keratoses (‘warts’)• Arsenical keratoses• Keratoacanthoma• Intra-epidermal
carcinoma (Bowen’s disease)
• Lentigo maligna