Occupational Dermatoses Flashcards
what causes the majoirty of occupational dermatoses?
Contact Dermatitis
What are the most common causes of ACD in occupational dermatoses?
Rubber> nickel>epoxy + resins> aromatic amines
MC cause of occupational irritant ICD?
Soaps> wet work> petroleum products> solvents> cutting oils> coolants
History components that lead you to occupational dermatoses?
Gets better when away from work, when chronic this is less clear cut. Covered areas are unusual sites of dz onset. Spread to distant sites is more common in ACD.
How do you make the dx of ACD from the workplace?
Test with work materials. You can do dilutional series with the testing if unknown substances to confirm that the rxn is allergic rather than irritant
What is a risk factor for ICD?
Prior eczema
What are two chemicals that can have a delayed-type chemical burn/irritant rxn?
Phenol and hydrofluoric acid
4 strong acids used in the workplace that can cause ICD?
sulfuric, nitric, hydrochloric, chromic
What is the mechanism for damage from strong acids?
Coagulate skin proteins –> forms barrier that impedes further penetration
hydrofluoric acid though can cause liquefactive necrosis and penetrates down to the bone.
How do you neutralize hydrofluoric acid?
calcium gluconate gel
What are some strong alkalis?
Sodium, calcium, potassium hydroxide, wet cement, sodium + potassium cyanides
What are alkalis worse than acids?
Degradation of lipids + saponification of resulting fatty acids form soaps–> aid penetration of alkalis deeper into skin.
what are some organic and inorganic chemicals that can cause chemical burn?
Dichromates, arsenates, phenolic compounds
How do Dichromates, arsenates, phenolic compounds cause damage in the skin?
Nerve damage –> anesthesia but rarely in the absence of visible skin damage -Vasoconstriction may lead to the necrosis that occurs–> systemic shock–>renal damage
Some solvents and gasses that can cause ICD?
Acrylonitrile, ethylene oxide (sterilize med supplies), carbon disulfide, mustine
What is the treatment for chemicals leading to chemical burns?
Initial: irrigation w/ large volumes of water (If insoluble to water, use soap solution) Avoid high pressure (splashes) Hydrofluoric acid: 2.5% calcium gluconate gel Chromic acid: early debridement of necrotic areas
What is the problem with latex patch testing?
It is not specific, there are lots of false negatives
If you have an allergy to peach, what other fruits are you allergic too potentially (cross react)
Other Rosaceae fruit (apple, pear, cherry, plum)
Biggest causes of contact urticaria?
cow dander, latex, food products
what risk factors in occupations can lead to SCC/BCC?
UV exposure is the key in 95%
Those at risk:
outdoor workers (agriculture and building industries), welders (UV exposure)
Polycyclic hydrocarbons ( tars, pitches, oil fractioning products)
Arsenic in glass production, copper, zinc or lead smelting, pesticide, herbicides and semiconductors
Radiologists, dentists, x-ray tech, radioactive materials
What are the clinical findings of occupational acne?
Open and closed comedones, non-inflamed nodules and cysts
Causes of occupational acne?
oils, halogenated polycyclic hydrocarbons, and repeated frictional trauma
Most common cause of occupational acne?
Oil acne
What is the occupational acne called that is caused by friction/truama?
Acne mechanica (frictional trauma occludes follicles at sites of pressure)
What is acne cosmetica?
Caused from things like lanolin, petrolatum, veggie oil you get smalled closed comedones, small papules and pustules
What are m/c causes of chloracne?
2/2 toxic chemicals and is a cutaneous sign of systemic exposure (chlorinated aromatic hydrocarbons)
2/2 2,3,7,9 tetrachlorodibenzo-p-dioxin (2,3,7,8 TCDD), agent orange, dioxin poisoning (Ukrainian president)
Clinical of chloracne?
Open comedones more than closed + concentration over malar crescent and behind ears, axilla, scrotum, penis
- Occurs w/I 2mo of exposure, lasts for years
- Fades slowly after exposure but severe dz persist for years
Acne 2/2 Halogens
Iodides, bromides, other halogens (iododerma more severe)
Treatment for chloracne?
avoidance of cause, isotretinoin, topical retinoids
What is vibration white finger?
Operators of chainsaws, pneumatic tools, hand grinders who work in cold
½ workers can be affected
Pathogenesis
Vibration between 30-300Hz a/w this
Increased activity of the sympathetic nervous system
Smoking contributes
Symptoms
Onset w/I 3 mo to 2.5 years
White patch of skin in response to cold-induced vasospasm (well demarcated)
Decreased sensation 2/2 touch receptors loos of blood supply
Improves with rewarming
Attacks not triggered by the tool
Thumbs usually spared
Grading
Stage 1: fingertips
Stage 2: partial digit
Stage 3: whole digit
Stage 4 trophic changes and ulceration
Common infections seen in healthcare workers?
herpetic whitlow, scabies, syphilis, AIDS
Common infections are seen in farmer/abattoir worker/veterinarian?
Orf, Milker’s nodule, brucellosis (parapoxvirus, brucella suis; b abortus; B. melitensis)
Common infection seen in farmers, wool sorter, dock worker, butcher?
Anthrax (bacillus anthracis) common in cattle, sheep, goats, horses, buffalo, camels
Common infection in Fisherman, tropical fish worker, fish market worker?
Mycobacterium marinum
Common infections in Butcher, abattoir worker, meat and fish packers?
Butcher’s warts: HPV 7
impetigo (Staph aureus)
Erysipelas (GAS)
Most common infections in a Fisherman, abattoir worker, farmer, butcher, cook, veterinarian?
erysipeloid (erysipelothrix rhusiopathiae) in shellfish, fish, birds and mammels (esp pigs).
If a fisherman gets cellulitis what must you be worried about potentially?
vibrio vulnificus
What infections could a farmer and veterinarian get?
microsporum canis (from cats, dogs)
M. nanum (pigs)
Trichophyton mentagrophytes (small mammels)
T. Verrucosum (Cattle)
T. Gallinae (chickens)
