Bilateral hearing loss after dichloromethane poisoning: a case report

Sudden hearing loss following acute carbon monoxide poisoning: A case report and literature review

Introduction:

Acute carbon monoxide (CO) poisoning could lead to headache, dizziness, myocardial injury, neurological sequela, and death. Sudden hearing loss is a rare symptom of acute CO poisoning.

Case Presentation:

Here, we report a case of a 42-year-old woman who suffered from acute hearing loss after exposure to a suicidal environment of high concentration of CO. Partial recovery of hearing was demonstrated after a combination of corticosteroid and hyperbaric oxygen therapy was given.

Discussion:

The mechanism of sudden hearing loss caused by acute CO poisoning is not well-established. It is believed to be related with the hypoxic damage to the cochlea. The characteristic of sudden hearing loss caused by acute CO poisoning is that it often affects in high frequency bilaterally.

Conclusion:

This report would prompt the clinician in early recognition of this sudden hearing loss of uncommon etiology.

Cochlear dysfunction is associated with styrene exposure in humans

AIM

Occupational exposure to styrene has been shown to be associated with an increased probability of developing hearing loss. However, the sites of lesions in the auditory system in humans remain unknown. The aim of this study was to investigate the possible adverse effects of styrene exposure on the cochlea of human subjects.

DESIGN

The hearing function of 98 styrene-exposed male workers from the glass fibre-reinforced plastics industry (mean concentration of 55 mg/m3) was evaluated bilaterally using pure-tone audiometry (1000-16000 Hz), distortion product otoacoustic emissions (DPOAEs), and auditory brainstem response (ABR). The results were compared to a group of 111 male workers exposed to noise (above 85 dBA) and 70 male white-collar workers exposed to neither noise nor solvents. Age and noise exposure levels were accounted for as confounding variables in all statistical models.

RESULTS

Styrene exposure was significantly associated with poorer pure-tone thresholds (1-8 kHz), lower DPOAE amplitudes (5-6 kHz), and shorter wave V latencies in both ears compared to control-group subjects. Similar results were found among noise-exposed subjects. A further analysis with wave V latency showed that styrene-exposed subjects showed significantly shorter latencies than expected according to normative data. These results suggest that occupational exposure to styrene at moderate concentrations is associated with cochlear dysfunction, at least at high frequencies. DPOAEs may be considered a valuable diagnostic tool in hearing conservation programs in workers exposed to styrene.

Accidental poisoning by intramuscular injection of dichloromethane and trichloroethylene: A case report

Introduction:

Dichloromethane (DCM) and trichloroethylene (TCE) are both common halohydrocarbons which are widely used in industry. The most common exposure route of DCM or TCE is inhalation, but intramuscular injection of DCM and TCE is very rarely.

Case presentation:

A 47-year-old male presented ecchymosis, pain, and swelling of the left limb following accident injection of ABS glue (main ingredients were DCM and TCE). The swelling of his left limb was lasted until day 6 and WBC, NEUT, CK, CK-MB, LDH, AST and ALT were elevated until day 9. He was received intravenous fluids, analgesic, antibiotics, and other supportive measures and finally discharged from the hospital on day 16.

Discussion:

Both DCM and TCE could cause local irritation and systemic toxicity involving central nervous system, liver, kidney and other organs. In this case, because the small dose of toxicant and injection being the route of exposure, the patient mainly suffered from local toxicity resulting in painful soft tissue swelling with slight hemocytology and biochemistry disorder. Although there are no specific antidotes for DCM and TCE poisoning, supportive measures may also provide satisfactory therapeutic results.

Conclusions:

DCM and TCE poisoning following intramuscular injection could present mainly with local and system poisoning symptoms and successfully treated with supportive measures.

IgA nephropathy in a laboratory worker that progressed to end-stage renal disease: a case report

Background

IgA nephropathy (IgAN) is the most common form of glomerulonephritis, a principal cause of end-stage renal disease (ESRD) worldwide. The mechanisms of onset and progression of IgAN have not been fully revealed, and epidemiologic studies have yielded diverging opinions as to the role of occupational exposure to organic solvents in the initiation or worsening of IgAN. As the authors encountered a laboratory worker with IgAN that progressed to ESRD, we present a case report of IgAN progression due to dichloromethane exposure along with a review of literature.

Case presentation

A 41-year-old male laboratory worker began to experience gross painless hematuria after two years of occupational exposure to toluene. Although clinical follow-up was initiated under the impression of IgAN based on clinical findings, the patient continued to work for four more years in the same laboratory, during which he was in charge of laboratory analysis with direct exposure to a high concentration of dichloromethane without proper protective equipment. During that time, his renal function rapidly worsened and finally progressed to ESRD 10 years after the first clinical symptoms. The result of exposure assessment through reenactment of his work exceeded the occupational exposure limit for dichloromethane to a considerable degree.

Conclusions

The causal association between occupational solvent exposure and IgAN is still unclear; therefore, this case report could be used as a basis to support the relevance of occupational solvent exposure to IgAN and/or its progression. Early intervention as well as close monitoring of laboratory workers exposed to various organic solvents is important to prevent or delay the progression of glomerulonephritis to ESRD in the occupational setting.