Severe bradycardia and prolonged hypotension in ciguatera.

Ciguatera results when ciguatoxin-contaminated coral reef fish from tropical or subtropical waters are consumed. The clinical features that present in affected persons are mainly gastrointestinal, neurological, general, and much less commonly, cardiovascular. We report the case of a 50-year-old man who developed the characteristic combination of acute gastrointestinal and neurological symptoms after the consumption of an unidentified coral reef fish head. In addition to those symptoms, he developed dizziness, severe bradycardia (46 bpm) and prolonged hypotension, which required the administration of intravenous atropine and over three days of intravenous fluid replacement with dopamine infusion. Patients with ciguatera can develop severe bradycardia and prolonged hypotension. Physicians should recognise the possible cardiovascular complications of ciguatera and promptly initiate treatment with intravenous atropine, intravenous fluid replacement and inotropic therapy if such complications are observed.

Minimal change disease caused by exposure to mercury-containing skin lightening cream: a report of 4 cases.

Mercury is a known cause of nephrotic syndrome and the underlying renal pathology in most of the reported cases was membranous nephropathy. We describe here 4 cases of minimal change disease following exposure to mercury-containing skin lightening cream for 2 - 6 months. The mercury content of the facial creams was very high (7,420 - 30,000 parts per million). All patients were female and presented with nephrotic syndrome and heavy proteinuria (8.35 - 20.69 g/d). The blood and urine mercury levels were 26 - 129 nmol/l and 316 - 2,521 nmol/d, respectively. Renal biopsy revealed minimal change disease (MCD) in all patients. The use of cosmetic cream was stopped and chelation therapy with D-penicillamine was given. Two patients were also given steroids. The time for blood mercury level to normalize was 1 - 7 months, whereas it took longer for urine mercury level to normalize (9 - 16 months). All patients had complete remission of proteinuria and the time to normalization of proteinuria was 1 - 9 months. Mercury-containing skin lightening cream is hazardous because skin absorption of mercury can cause minimal change disease. The public should be warned of the danger of using such products. In patients presenting with nephrotic syndrome, a detailed history should be taken, including the use of skin lightening cream. With regard to renal pathology, apart from membranous nephropathy, minimal change disease should be included as another pathological entity caused by mercury exposure or intoxication.

Aconite poisoning over 5 years: a case series in Hong Kong and lessons towards herbal safety.

BACKGROUND: Aconite poisoning is a severe, life-threatening poisoning related to the use of traditional Chinese medicine (TCM). Despite current legislation, repeated poisoning cases are steadily encountered. OBJECTIVE: The aim of the study was to summarize the clinical features and to elucidate the causative and contributory factors leading to aconite poisoning. METHODS: This study was conducted within the Hospital Authority Toxicology Reference Laboratory, which is the sole tertiary referral clinical toxicology laboratory in Hong Kong. This retrospective study reviewed all confirmed aconite poisoning cases handled by a clinical toxicology laboratory between April 2004 and July 2009. The diagnosis in all cases was confirmed biochemically by detecting aconitum alkaloids in urine specimens. Additionally, herbal specimens were morphologically identified and herbal formulae were studied and transcribed. The cause of poisoning for each case was determined whenever possible. RESULTS: Fifty-two cases were examined in this aconite poisoning case series. Neurological, cardiovascular and gastrointestinal toxicities were encountered in 49 (94.2%), 46 (88.5%) and 31 (59.6%) patients, respectively. The poisoning was severe in 6 (11.5%) patients, moderate in 17 (32.7%) patients and mild in 29 (55.8%) patients. Amongst 44 patients (84.6%) in whom the underlying reasons of poisoning could be determined, four major causes were found. These included overdose - prescription of a higher than recommended dosage of aconite herbs in 17 (32.7%) cases; 'hidden' poisoning (the aconite herb was not prescribed but dispensed inadvertently) in 17 (32.7%) cases; usage of inadequately processed herbs in 7 (13.5%) cases; and dispensary error in 2 (3.9%) cases. No case fatality was recorded. CONCLUSION: In the majority of cases in this series, the causes of poisoning can be traced to poor-quality herbs, poor quality of prescription practice, or dispensary errors. The quality issues of TCM practice should be critically addressed to minimize this poisoning threat.

Seasonal pattern of tuberculosis in Hong Kong.

BACKGROUND: Summer predominance of tuberculosis (TB) was reported previously in temperate regions. No consistent data were available for lower latitudes. METHOD: The monthly TB notification data in Hong Kong from 1991 to 2002 were examined for seasonal fluctuation. A seasonal model was then developed after standardization by period, sex, age, history of TB, form of disease, and bacteriological status. RESULTS: The raw monthly counts showed remarkably consistent seasonal fluctuation across different periods, sexes, and age groups. A sine model was fitted for 82 104 notifications (adjusted R(2) = 0.373, P < 0.001). A summer peak was observed with seasonal fluctuation of 18.4% (P < 0.001), which was substantially higher than that reported previously for temperate regions. The amplitudes of fluctuation were 35.0, 15.0, 19.0, and 20.2% for those aged < or =14, 15-34, 35-64, and >/=65 years, respectively (all P < 0.001). No gender difference was noted (18.2% vs 19.0%, P = 0.790). Seasonal pattern was detected among new cases (18.6%, P < 0.001), but not retreatment cases (5.2%, P = 0.333). Culture-positive cases showed greater fluctuation than culture-negative cases (29.4% vs 6.4%, P < 0.001). No significant difference was found between pulmonary and extrapulmonary cases (16.8% vs 21.6%, P = 0.356). TB cases notified in summer were more likely to be smear-positive [odds ratio (OR) 1.100, 95% confidence interval (CI) 1.045-1.158, P < 0.001] and culture-positive (OR 1.175, 95% CI 1.121-1.232, P < 0.001) than those notified in winter, even after stratification by other key variables. CONCLUSION: A consistent seasonal pattern was found, with variable amplitudes of fluctuation in different subgroups and differing disease characteristics in different seasons. These observations are suggestive of the presence of a seasonal disease-modifying factor.