This Initial Check will help you to assess your current knowledge about chromium toxicity. To take the Initial Check, read the case below, and then answer the questions that follow.
A 35-year-old handyman has chronic skin ulcers and respiratory irritation.
A 35-year-old man visits your family practice office near a large Midwestern city. He has complaints of “allergies” and sores on his hands and arms. Over the past 2 to 3 months, the patient has noticed the onset of runny nose, sinus drainage, dry cough, and occasional nosebleeds (both nares intermittently). No prior history of allergies exists. He has also had occasional nausea and is concerned because the sores and minor skin cuts on his hands do not seem to heal. The patient denies having fever, chills, dyspnea, or change in bowel or bladder habits, and he has not noticed excessive thirst or easy bruising. He recently began losing his appetite and losing weight without dieting.
With the exception of the complaints mentioned, review of systems is otherwise unremarkable. The patient has used various over-the-counter remedies for his respiratory problems without relief. He did, however, note significant improvement in symptoms when he visited his sister in Chicago for 5 weeks at the end of the summer.
Medical history reveals only usual childhood diseases. Other than over-the-counter (OTC) decongestants, he is taking no medications. He denies use of illicit drugs, but admits to occasional social use of alcohol. For the last 16 years, he has smoked 1 pack of low-tar cigarettes a day.
The patient has been employed as a mathematics teacher for 13 years; he usually works summers as a self-employed handyman. His hobbies include reading and tennis. Two years ago he moved into a ranch-style house several hundred yards from a small manufacturing plant; a small pond sits between his house and the plant. The house has central air conditioning and gas heat; it is supplied with well water and uses a septic sewage system. Four months ago, the patient began digging up the sewage system to make repairs. Shortly after he began digging, he first noticed the sores on his hands and forearms.
Physical examination reveals an alert white male with 10 erythematous papules of 5-10 millimeters in diameter located bilaterally on the dorsal forearm and hands; edema of the hands is present. The dermal lesions show small circular areas with shallow ulcerated centers. Ear, nose, and throat examination is unremarkable, and chest examination reveals a few scattered rhonchi that clear with coughing. His liver is slightly enlarged and tender to palpation. Cardiovascular, genitourinary, rectal, and neurologic examinations are unremarkable.
Initial laboratory findings include evidence of 2+ proteinuria and hematuria, and slightly elevated bilirubin, aspartate aminotransferase [AST]; known as serum glutamic-oxaloacetic transaminase (SGOT), and alanine aminotransferase (ALT); known as serum glutamic-pyruvic transaminase (SGPT). Scrapings of the dermal lesions, done with potassium hydroxide preparation, show no fungal elements on microscopic examination. A nasal smear for eosinophils is within normal limits.
- Formulate an active problem list for this patient.
- What clues indicate that this case might have an environmental etiology?
- What further information will you seek before making a diagnosis?
- In addition to the patient, who in the case study might be at risk of chromium exposure?
- On further questioning, the patient described in the case study relates that when he had reached several feet in depth while digging to repair the sewage system, he noticed an oozing from the ground of sometimes yellowish sometimes greenish water; this persisted throughout the several weeks of digging. The nearby pond, which is murky, also has a generally yellow tint, at times with small areas of greenish color. Suspecting an environmental link, you contact the local health department. Levels of chromium are found in the pond water that exceed corresponding health screening values, and the investigators inform you that the nearby plant is electroplating auto parts with chromium. Discuss all sources and pathways by which this patient might be exposed to chromium.
- Analysis of blood and urine specimens from the patient described in the case study reveals elevated Cr(III) serum and urine concenÂtrations. Assuming that the patient was exposed only to Cr(VI), explain the presence of Cr(III) in each of these body fluids.
- Could chromium toxicity account for the symptoms experienced by the patient described in the case study? Explain.
- Is the patient at increased risk of chromium-induced lung cancer?
- Analysis of the tap water in the patient’s home reveals a greenish tinge and a chromium concentration of 746 micrograms per liter. Your diagnosis is chromium toxicity. Are there any other tests the patient should undergo?
- The patient described in the case study insists on obtaining a hair analysis. The chromium content of the hair sample is 1,038 parts per million (ppm). How will you interpret this result?
- What is the recommended treatment for the patient described in the case study?
- A problem list for this patient would include upper and lower respiratory irritation, multiple skin lesions and edema of the hands, loss of appetite and weight loss, liver and renal dysfunction, and cigarette smoking.More information for this answer can be found in the “What are the physiologic effects of chromium?” section.
- Information suggesting an environmental etiology includes the following: onset of the patient’s symptoms coincides with activity outside the usual routine; in addition, the patient mentions that he first noticed the sores on his hands and forearms while digging up the sewage system to make repairs. Another clue to a possible environmental cause is temporary relief of symptoms when the patient leaves his usual habitat, such as when he visited Chicago. Proximity of the patient’s home to an industrial facility (i.e., the electroplating plant) is also an important clue.More information for this answer can be found in the “Where is chromium found?” section.
- You might identify possible causes for the dermal lesions by consulting with a dermatologist. The cause of the persistent respiratory symptoms (2 to 3 months) that do not respond to OTC decongestants in a person with no history of allergies should be pursued. The patient should be queried about whether the onset of symptoms coincided with the move to his home, whether odors have emanated from the plant, and so forth. More information regarding the patient’s observations and activities while digging up the sewage system may also be helpful.More information for this answer can be found in the “Clinical assessment – history and signs and symptoms” section.
- If effluent from the plant has reached the groundwater, community residents who drink well water might be at risk. Airborne plant emissions might have also reached nearby residents. Plant workers who are exposed to the plating baths and work near them might be receiving significant exposure.More information for this answer can be found in the “Who is at risk of exposure to chromium?” section.
- The most important pathways for possible chromium exposure in this case are dermal contact during the unearthing of the sewage system; inhalation of emissions from the plant or soil particles if the pond dries up; and ingestion, if the drinking water has been contaminated by effluents from the plant. Minor inhalation sources of chromium might include road and cement dust, erosion products of brake linings and emissions from automotive catalytic converters, and tobacco smoke. Foodstuffs (ingestion) generally contain extremely low chromium levels.More information for this answer can be found in the “What are routes of exposure for chromium?” section.
- Cr(VI) is a powerful oxidizing agent. In the plasma and cells, it is readily reduced to Cr(III), which is excreted in the urine.More information for this answer can be found in the “What is the biologic fate of chromium in the body?” section.
- Yes. Persistent dermal ulcers, respiratory tract irritation, and pulmonary sensitization are all possible effects of chromium exposure.More information for this answer can be found in the “What are the physiologic effects of chromium exposure?” section.
- The potential risk of chromium-induced respiratory system cancer from non-occupational exposure to Cr(VI) must be determined on a case-by-case basis. It is unlikely that the inhalation chromium exposure of this patient will cause lung cancer, although it cannot be ruled out. The patient should be advised to stop smoking cigarettes because smoking may act synergistically to increase risk and is itself a significant risk factor for lung cancer.More information for this answer can be found in the “What are the physiologic effects of chromium exposure?” section.
- If exposure was recent, chromium levels in blood or urine may be used to confirm exposure. Renal function should be tested (urinalysis, blood urea nitrogen, creatinine, and â2-microglobulin) to determine if renal tubular damage has occurred.More information for this answer can be found in the “Clinical assessment-laboratory tests” section.
- A result of 1,038 ppm is beyond the range for unexposed persons (50 ppm to 1,000 ppm); however, the sample could have been environmentally contaminated with chromium from the water during bathing, or by chromium in ambient air polluted by the plant emissions. No standard methods exist for obtaining a hair sample or for washing and preparing the sample for analysis, and these techniques can greatly influence results. More importantly, no research exists to prove a correlation between chromium content of hair and exposure levels or physiologic effects; therefore, the result has no clinical significance.More information for this answer can be found in the “Clinical assessment-laboratory tests” section.
- If the sources of chromium exposure can be eliminated for this patient, no further treatment would be required, except for the skin lesions. Topical ascorbic acid has been useful in the treatment of chrome ulcers, and 1% aluminum acetate wet dressings can be used to treat the dermatitis.This patient’s case might be a sentinel for community exposure. You should contact the local health department, the Occupational Safety and Health Administration, and U.S. Environmental Protection Agency (EPA) to report your patient’s adverse effects and discuss your suspicions of the chromium source. Chromium levels in and around the plant should be measured. It should be ensured that workers exposed to Cr(VI) are provided proper protective gear, trained, and medically monitored. Because EPA does not have an emission standard, it might be difficult to abate the atmospheric source of chromium. Decontamination of the pond might require regulatory action and litigation. Residents who use well water should be encouraged to use an alternative water source for drinking, cooking, and showering/bathing and any other use that results in dermal or oral exposure.More information for this answer can be found in the “How should patients exposed to chromium be treated and managed?” section.