Best Dx/Best Rx: Occupational Medicine

From: Subject: Best Dx/Best Rx: Occupational Medicine Date: Wed, 3 Jun 2009 21:50:19 -0700 MIME-Version: 1.0 Content-Type: multipart/related; type="text/html"; boundary="----=_NextPart_000_0262_01C9E495.49A06C00" X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0262_01C9E495.49A06C00 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Content-Location: http://www.acpmedicine.com/acp/newrxdx/rxdx/dxrx0006.htm Best Dx/Best Rx: Occupational Medicine

Occupational=20 Medicine

Linda Rosenstock, M.D., M.P.H., F.A.C.P. = University=20 of California, Los Angeles, School of Public Health =
Mark R. Cullen, M.D. Yale University School of=20 Medicine

Defin= ition/Key=20 Clinical Features
Diffe= rential=20 Diagnosis (Causes of Dyslipidemia)
Best = Tests
Best = Therapy
Best = References

Definition/Key=20 Clinical Features

Most occupational disorders are pathologically = indistinguishable from disorders with more familiar causes=20
It is almost always possible to differentiate=20 occupational diseases from their nonoccupational counterparts=20
Both the likelihood that workplace hazards = will produce=20 effects and the severity of those effects are determined by the dose = of=20 exposure=20
Host factors may modify temporal and = dose-response=20 correlations=20
Many workplace hazards and toxins interact = with one=20 another and with nonoccupational factors in the induction of = disease=20

bac= k to=20 top

Differential = Diagnosis

Common = Occupational Disorders=20 (Examples of Causal Factors)=20

Respiratory tract=20
- Pneumoconiosis (coal, silica, = asbestos)=20
- Asthma (latex, polyurethane)=20
- Allergic alveolitis (vegetable matter, = machining=20 fluids)=20
- Metal fume fever (metal fumes) =
Skin=20
- Contact dermatitis (oils, rubber, = metals)=20
- Acne (herbicides, oils, friction)=20
- Urticaria (latex, formaldehyde, = nickel)=20
Urinary tract
- Glomerular disease (organic solvents, = mercury)=20
- Tubulointerstitial disease (cadmium, = lead)=20
Liver=20
- Hepatoportal sclerosis (vinyl chloride, = arsenic,=20 thorium)=20
- Acute or subacute necrosis (organic = solvents, TNT,=20 2-nitropropane)=20
- Cholestatic hepatitis (methylene = dianiline)=20
- Acute and chronic hepatitis (viruses = [hepatitis B,=20 C])=20
- Granulomatous hepatitis (beryllium, = copper)=20
- Steatosis (organic solvents)=20
- Hepatocellular injury (lead, arsenic, = phosphorus,=20 dioxin)
Musculoskeletal=20
- Carpal tunnel syndrome (repetitive = trauma)=20
- Raynaud phenomenon (repetitive vibrations, = vinyl=20 chloride)=20
- Scleroderma (coal mining)
Nervous system=20
- Parkinsonism (manganese)=20
- Peripheral neuropathy (solvents, lead, = acrylamide,=20 arsenic, organophosphates)=20
- Acute encephalopathy (organic solvents,=20 asphyxiants)=20
- Acute or subacute cholinergic crisis = (organophosphate=20 and carbamate pesticides)=20
- Subacute encephalopathy (mercury, lead, = arsenic,=20 manganese, carbon disulfide)=20
- Subacute peripheral neuropathy=20 (organophosphates)=20
- Chronic basal gangliar disorder (manganese, = carbon=20 monoxide [postasphyxiation])=20
- Chronic encephalopathy (recurrent exposures = to organic=20 solvents)
Hematologic conditions=20
- Hemolysis (lead, organic nitrites)=20
- Acute hemolysis (nitro and amine = compounds)=20
- Subacute hemolysis (lead)
Disorders of oxygen transport=20
- Methemoglobinemia (nitro and amine = compounds)=20
- Carboxyhemoglobinemia (carbon = monoxide)=20
Disorders of red cell production=20
- Hyperplastic anemia (lead)=20
- Aplastic anemia, hypoplastic anemia = (ethylene glycol=20 ethers, benzene, arsenic, ionizing radiation, lindane)
- Myelodysplasia (benzene, ionizing = radiation)=20
- Polycythemia (cobalt, carbon = monoxide)
Infectious=20
- Hepatitis B, C (health care work)=20
- Influenza A (e.g., H5N1) (poultry = work)=20
- SARS (health care work)=20
- Anthrax (handling of animals) =
Endocrine and reproductive=20
- Hypogonadism (lead)=20
- Azoospermia, oligospermia (DBCP [pesticide], = ionizing=20 radiation)=20
- Teratogenesis (organic mercury, PCBs) =

Established and Probable = Occupational=20 Carcinogens (Examples of Sources of Exposure)=20

Lung=20
- Asbestos (insulation, textiles)=20
- Ionizing radiation (uranium mining)=20
- Arsenic (refining)=20
- Polyaromatic hydrocarbons (coke = ovens)=20
- Nickel (nickel refining)=20
- Chromium (tanning, pigments)=20
- Alkylating agents (chemical industry) =
- Silica mining (stonecutting)
- Ceramic fibers (insulation)=20
- Formaldehyde (chemicals, plastics)=20
- Beryllium (nuclear weapons, aerospace = industry)=20
- Cadmium (batteries)=20
- Environmental tobacco smoke=20
- Acrylonitrile (plastics)=20
- 1,3-Butadiene (rubber, plastics) =
Pleura and peritoneum=20
- Asbestos (construction materials) =
Upper respiratory tract=20
- Wood dust (carpentry)=20
- Nickel (refining)=20
- Cutting oils (machinists)=20
- Chromium (plating)=20
- Asbestos (friction products)=20
- Formaldehyde (chemicals, plastics) =
Urinary bladder=20
- Benzidine and related amines (dyes, = chemicals)=20
- Arsenic (pesticides)=20
- Coal tars (roofing)=20
- Polyaromatic hydrocarbons (aluminum = production)=20
Liver=20
- Vinyl chloride monomer (plastics)=20
- Arsenic (pesticides)
Colorectal=20
- Asbestos (shipbuilding)=20
- Wood dust (furniture)=20
- Rubber (rubber manufacturing) =
Hematologic system=20
- Benzene (chemicals, rubber)=20
- Ionizing radiation (defense industry, health = care=20 work)=20
- Ethylene oxide (chemicals, = sterilizers)=20
Soft tissue=20
- Dioxin (chemical industry)
Brain=20
- Vinyl chloride (chemical industry)=20
- Formaldehyde (chemical industry)=20

bac= k to=20 top

Best=20 Tests

Ask the following questions:=20
- Is the clinical illness, including the = history,=20 physical examination, and laboratory findings, consistent with other = case=20 descriptions?=20
- Is the timing between exposure and clinical = onset=20 compatible with the known biologic facts about the hazard?
- Is the exposure dose within the range of = doses=20 believed to cause such effects?
- Are there special attributes of the = particular patient=20 that make it more or less likely that he or she would be so = affected?=20
- Are there alternative ways of constructing = the case=20 that better fit the available facts?
- Where there remains significant uncertainty = about the=20 cause, how important is it to be certain?
Every patient should be questioned regarding = the=20 essentials of occupation, including current and past workplaces, job = type, and=20 materials used
Tests for exposure can be interpreted only in = the=20 context of the history and clinical problem

Common Occupational Hazards for Which There Are Widely = Available=20 Biologic Tests of Exposure=20

Metals=20
- Arsenic=20
  - Transient in urine=20
  - Hair sampling can detect past = exposures=20
- Cadmium=20
  - Detectable in urine for many years if = there is renal=20 injury=20
  - Half-life in blood, 100 days =
- Fluorides=20
  - Transient in urine
- Lead=20
  - Half-life in blood, 40 days=20
  - Half-life in bone, years (measured by = x-ray=20 fluorescence)
- Mercury=20
  - Detectable in urine for days to = weeks=20
- Carbon monoxide=20
  - Half-life in blood, 4 hr
- Organophosphate (pesticide)=20
  - Detectable indirectly by measurement of=20 cholinesterase (may be depressed for days to months) =
- Organic solvents=20
  - Benzene and toluene=20
    - Metabolites transiently in urine =
  - Trichloroethylene and = perchloroethlylene=20
    - In blood and metabolites in urine =
- Antigens: IgE antibodies measurable by=20 radioallergosorbent test (RAST)
- PCBs: persists in blood=20

bac= k to=20 top

Best=20 Therapy

Therapy depends on specific disorder=20
Remove patient from exposure to causal = hazard=20

bac= k to=20 top

Best References

Pascarelli EF, et al: J Occup Rehabil 11:1, 2001 = [PMID=20 11706773]

Rabatin JT, et al: Mayo Clin Proc 76:633, 2001 = [PMID=20 11393503]

Rutchik JS, et al: Clin Occup Environ Med 4:621, = 2004 [PMID=20 15465472]

Textbook of Clinical Occupational and=20 Environmental Medicine, 2nd ed. Rosenstock L, et al, Eds. Elsevier = Saunders Co,=20 London, 2005