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Biomedical subjects

C L Goh

Publications and source records attributed to C L Goh.

At least 19 recordsLinked to original sources

Evaluation of enzyme immunoassay for the detection of anogenital infections caused by Chlamydia trachomatis.

BACKGROUND--Infection caused by Chlamydia trachomatis is now recognised as the most prevalent sexually transmitted disease in many parts of the world. Anorectal infections caused by C. trachomatis is not uncommon. Enzyme-linked immunoassay (EIA) detects an antigen lipopolysaccharide (LPS) of C. trachomatis directly in clinical specimens. OBJECTIVE--Our aim was to compare an enzyme immunoassay, Wellcozyme Chlamydia (WZ04) with cell culture for the diagnosis of chlamydial infection of the anogenital tract. METHOD--Rectal swabs were taken from 100 prostitutes (80 females and 20 males) for chlamydia culture, WZ04 and direct immunofluorescence (DIF). In addition, endocervical specimens were obtained from the females for the above three tests. MAIN FINDINGS--All the positive rectal specimens were from females. Nine patients had a positive chlamydia culture from the rectum but negative WZ04 and DIF. Two patients had false positive results by WZ04 but negative culture and DIF. For cervical specimens, WZ04 identified 43% (3/7) of the culture positive cases. Specificity was 98.6%. WZ04 identified an additional specimen as positive which was also confirmed as positive by DIF. CONCLUSION--Our study shows that in our hands enzyme-linked immunoassays such as Wellcozyme Chlamydia are neither sensitive nor specific in detecting C. trachomatis infection of the rectum. For cervical infections, the sensitivity of WZ04 was 43% and the specificity 98.6% as compared to culture, with a positive predictive value of 75% and a negative predictive value of 94.7%.

Adult

The incidence of cutting fluid dermatitis among metalworkers in a metal fabrication factory: a prospective study.

We compared the incidence of occupational dermatitis and transepidermal water vapour loss (TEWL) changes from cutting fluids (neat mineral oils) in 24 new machinists with 27 armed forces paramedics (controls) over a 6-month period. The cumulative incidence of occupational dermatitis in positive controls increased from 38% at week 3 to 77% at week 6. It then decreased to 50% at week 9 and thereafter remained constant at about 50% throughout the remaining study period. 2 workers sought medical treatment for their dermatitis. Only 1 worker had a job transfer because of his dermatitis. None of the paramedics developed dermatitis during the study period. The mean basal TEWL values on the hands of machinists and controls were 17.6 and 14.5 g/m2/h (n.s.) respectively. The mean TEWL values of machinists increased to 22 g/m2/h by week 3 and then remained fairly constant throughout the remaining study period. The mean TEWL of negative controls remained fairly constant (at about 14 g/m2/h) from the beginning to the end of the study period. The mean TEWL value of machinists was significantly higher than that of negative controls throughout the study period. There was no significant difference in the prevalence of cutting fluid dermatitis between machinists with high basal TEWL values (> or = 17 g/m2/h) and those with low basal TEWL values (< 17 g/m2/h).

Adolescent

Efficacies of a barrier cream and an afterwork emollient cream against cutting fluid dermatitis in metalworkers: a prospective study.

We compared the point prevalence of cutting fluid dermatitis and transepidermal water vapour loss (TEWL) changes in groups of new machinists who (a) used a barrier cream; (b) used an afterwork emollient cream; and (c) did not use any cream (controls) over a 6-month period. All machinists handled cutting fluid (neat mineral oil) during their work. There was no significant difference in the prevalence of cutting fluid dermatitis in the 3 groups throughout the study period. The prevalence of cutting fluid dermatitis in all groups increased rapidly during the first 6 weeks and thereafter remained steady throughout the remainder of the study period. The prevalence of cutting fluid dermatitis was slightly lower in machinists using afterwork emollient cream compared to those using barrier cream and controls (not significant). The differences in the mean TEWL changes during the study period among the 3 groups were also not statistically significant. The mean TEWL values in the 3 groups increased rapidly during the first 6 weeks of exposure to cutting fluids and thereafter remained fairly constant throughout the remainder of the study period. Barrier cream and afterwork emollient cream did not appear to have any significant effect against either cutting fluid dermatitis or TEWL changes in machinists exposed to cutting fluid. However, afterwork emollient cream appeared clinically to help reduce the prevalence of cutting fluid irritation.

Adolescent

A study of occupational skin disease in the metal industry (1986-1990).

A retrospective study of the epidemiology of occupational skin disease among metal workers showed that irritant contact dermatitis (75%) prevailed over allergic contact dermatitis. Most workers belonged to the age group 20 to 29 years. There was a slight preponderance of Malays and Indians compared to the working population of Singapore. Most presented for treatment within 10 days of their dermatitis. Ninety-five percent presented with dermatitis on the hands and arms. There was no significant difference in the prevalence of atopy between workers with irritant and allergic contact dermatitis. In most cases of allergic contact dermatitis from cutting fluid, the causative allergen in the cutting fluid cannot be identified.

Adolescent

Common industrial processes and occupational irritants and allergens--an update.

This paper reviews the recent development of the industrial processes in the construction, electronics and metal industries which are the predominant industries in developing countries. Common occupational irritants and allergens are presented. The information is essential for occupational dermatologists and physicians managing patients with occupational skin diseases. In the construction industry, the prefabrication construction methods are now widely used. The commonest irritant is cement and the allergens are chromate, rubber chemicals and epoxy resins. In the electronics industry, the commonest irritants include soldering flux, solvent and fibreglass, and allergens include resins and metals, rubber chemicals and amines and colophony. Cutting fluid is the commonest occupational irritant in the metal industry. Biocides and metals in The electro-discharge machining process now widely used in the metal industry for precision engineering uses the electrodischarge machining fluids (EDM fluids) which are a strong skin irritant. Preventive measures including health education are most effective against occupational dermatitis.

Allergens

Etretinate therapy for psoriasis and other keratinizing disorders: a 10-year retrospective study in Singapore.

BACKGROUND: Etretinate, a second generation retinoic acid, has been reported to be useful in the treatment of psoriasis and other keratinizing disorders. The effectiveness of etretinate for these disorders are studied in a 10-year retrospective study of all patients treated with etretinate in a skin clinic in Singapore. METHODS: The case records of 190 cases of psoriasis and other keratinizing disorders treated with etretinate were analyzed. Information collected included demographic data, dosage of etretinate taken, response and side effects, clinical follow-up, and relapse. RESULTS: Most of the cases (72.6%) had psoriasis (138/190). The others had different keratinizing disorders. The dose of etretinate used was 0.15 to 1 mg/kg/day (median 0.36 mg/kg/day), and the duration of the treatment varied from 1 to 120 months (median 6 months). Etretinate was coadministered with UVB (ReUVB) or PUVA (RePUVA) in 89 (46.8%) patients. In psoriasis, the response to treatment was excellent in 41.3% (57/138), good in 36.2% (50/138), fair in 15.9% (22/138), and poor in 6.5% (9/138) of the cases. Patients with plaque-type psoriasis did better with combination therapy than with monotherapy. Those with keratinizing disorders showed excellent, good, fair, and poor responses in 32.7% (17/52), 32.7% (17/52), 25.0% (13/52), and 9.6% (5/52) respectively. Adverse effects were noted in 102 (53.7%) cases and were generally mild and tolerable. Etretinate was discontinued in 24 (12.6%) patients due to significant toxicity. CONCLUSIONS: Etretinate is effective for treating psoriasis and other keratinizing disorders. Combination therapy is preferred in chronic plaque psoriasis. Adverse effects are common, but mild and tolerable.

Adolescent

Pattern of skin diseases at the National Skin Centre (Singapore) from 1989-1990.

At the National Skin Centre, 74,589 new attendances were seen from 1989 to 1990. The M:F ratio was 1:1. The majority of the patients belonged to the 20-39 year age groups (40%). Frequencies of psoriasis (20.4%) and alopecia (17.2%) were higher among Indians; exfoliative dermatitis was higher among Malays (19.72%); and insect bites were higher among Chinese (87%) [P less than 0.05] compared with ethnic distribution (9.9%, 7.6%, and 77.2% respectively) of NSC patient population. Dermatitis (34.2%) and acne (10.9%) were the most common skin disorders seen. The more common dermatoses seen in 1989/90 differ slightly from those reported in 1950s and 1980s; however, the frequencies of contact dermatitis, fungal infection, and insect bite reactions of 5.8%, 10.9%, and 7.6%, respectively, in 1980 have decreased to 4.7%, 5.4%, and 2.3%, respectively, in 1989/90. There was no seasonal variation in the frequency of various dermatoses except for psoriasis, which was more prevalent during the first quarters of 1989 and 1990. Our results showed that the pattern of skin diseases in Singapore is slowly approximating that of developed countries. The changes in the pattern of skin diseases are probably due to improved economic status, better education and hygiene, ready availability of dermatology services, as well as changes in occupational and environmental contactants over the last decade.

Adult

Carbon dioxide laser treatment of periungual and subungual viral warts.

This is a retrospective study of the cure rates of forty patients with subungual and periungual viral warts treated with carbon dioxide laser vapourisation (total of 69 lesions). 70.6% (48/68) lesions had failed treatment with cryotherapy and/or electrocautery treatment previously. 20/68 were treated with CO2 laser vapourisation as a first line treatment. The overall cure rate over 10 months follow-up period was 57.4% (39/68). Most recurrences (24/25) occurred within the first 3 months of vapourisation. The carbon dioxide laser vapourisation cure rate for warts in which previous cryotherapy and/or electrocautery had failed was 47.9% whereas those treated with carbon dioxide laser vapourisation as a first line treatment had a cure rate of 80% (p = 0.043). Subungual warts responded slightly better with a cure rate of 64.7% compared with periungual warts (54.9%) (n.s.). The carbon dioxide laser vapourisation cure rate for recurrent subungual and periungual warts (which failed previous carbon dioxide laser vapourisation) was 73.3% (11/15). Our findings appeared to indicate that periungual and subungual warts can be eradicated by CO2 laser vapourisation. Recurrent warts can be effectively eradicated by further vapourisation. Recalcitrant periungual and subungual warts which have previously failed to respond to cryotherapy and/or electrocautery can be effectively eradicated with CO2 laser vapourisation.

Adolescent

Dermatophyte and non-dermatophyte onychomycosis in Singapore.

Onychomycosis is caused by dermatophytes, moulds and yeasts. It is important to identify the non-dermatophyte moulds as they are resistant to the usual anti-fungals. A prospective study was undertaken in the National Skin Centre, Singapore to study the pattern of dermatophyte and non-dermatophyte onychomycosis. 53 male and 47 female patients seen between June 1990 and June 1991 were entered into the study. Direct microscopy was done and the nail clippings were cultured. Toe and finger nails were equally infected. Dermatophytes were isolated from 21 patients namely, T. rubrum (12/21), T. interdigitale (5/21), T. mentagrophytes (3/21) and T. violaceum (1/21). Candida onychomycosis occurred in 39 patients and was caused by C. albicans (38/39) and C. parapsilosis (1/39). 37/39 patients had associated paronychia. 5 types of moulds were isolated from 12 patients, namely Fusarium species (6/12), Aspergillus species (3/12), S. brevicaulis (1/12), Aureobasilium species (1/12) and Penicillium species (1/12). Although the clinical pattern and microscopy may predict the type of organisms, in practice this is difficult. Only cultures were confirmatory. 28% (28/100) had negative cultures despite a positive microscopy, and moulds (12/100) grown might be contaminants rather than pathogens.

Adolescent

Changing trends in the epidemiology of contact dermatitis in Singapore.

All patients seen in the Contact Dermatitis Clinic of the National Skin Centre, Singapore (and the former Middle Road Hospital) between January 1986 and December 1990 were analysed retrospectively. 5557 patients comprising 2634 (47.4%) males and 2923 (52.6%) females were patch tested. 3154 (56.8%) patients had 1 or more positive reactions. The majority of the patients were Chinese (78.0%), followed by Malays (11.5%), Indians (8.1%) and other minority races (2.4%). The majority of positive reactions belonged to the 21-40 age group. The incidence of positivity decreased after 60 years. The commonest allergens responsible were nickel (17.7%), fragrance (13.3%), neomycin (6.9%), colophony (6.6%) and proflavine (6.5%). Both neomycin and proflavine were commonly used as over-the-counter medicaments. Compared to an earlier report in 1988, there were differences in the incidence of contact sensitivity to some allergens. Potassium dichromate, which used to be a common allergen, was less common. Some allergens (carba-mix, naphthyl-mix, caine-mix and PCMX) have been removed from our standard series as they were uncommon causes of contact allergy. Thimerosal and Amerchol L-101 were added in their place.

Adult

Comparative study of TRUE Test and Finn Chamber patch test techniques in Singapore.

This is a report on a comparative study of the reactivity of TRUE Test and Finn Chamber patch test techniques. 413 patients attending a contact dermatitis clinic in Singapore were simultaneously patch tested with panels 1 and 2 of the TRUE Test standard series and with corresponding allergens (Hermal, Hamburg) using Finn Chambers. The left/right application of the TRUE Test and Finn Chambers was randomized. The concordance of positive patch test reactions to the 2 test techniques was studied. The number of patient with positive reactions was 38% and 42% for TRUE Test and Finn Chamber techniques, respectively (n.s.). The overall concordance of positive patch test reactions was 64% (209/328). 13% (42/328) of positive reactions appeared on TRUE Test only and 24% (77/328) on Finn Chamber only. When only relevant positive reactions were considered, the concordance rate was 67%; 11.6% of positive reactions appeared on TRUE Test only and 21% on Finn Chamber only. Positive reactions to p-phenylenediamine (PPD) and neomycin were more frequent with the Finn Chamber technique than with TRUE Test, i.e., false negative reactions to PPD and neomycin were more likely to occur with TRUE Test. It appeared that the TRUE Test and Finn Chamber techniques were comparable when used for patch testing. However false negative and false positive patch test reactions can occur when using either technique.

Adolescent

Pattern of dermatophyte infection in Singapore.

Dermatophyte infection is the fourth commonest skin disorder seen in the National Skin Centre in Singapore. A prospective study was carried out from June 1990 to March 1991 to determine the epidemiology and pattern of dermatophyte infections seen in this centre. Two hundred patients who had a clinical diagnosis of dermatophyte infection and confirmed by direct microscopy were included into the study. Cultures for dermatophyte were done on Sabouraud's dextrose agar with chloramphenicol and cycloheximide. There were 148 male and 52 female patients, of whom 146 (73%) had a positive culture from one or more sites. One hundred and thirty-nine (95.2%) patients had dermatophyte infection while the remaining seven (4.8%) patients had non-dermatophyte infection. The sites involved were the groin (92 patients), feet (52 patients), trunk (26 patients), hands (18 patients), face (9 patients), legs (9 patients), scalp (8 patients) and axilla (7 patients). The commonest dermatophyte isolated was Trichophyton rubrum (81/139). It was also the commonest organism isolated in all the sites except the scalp. The other dermatophytes grown were, in order of frequency, Trichophyton interdigitale (21/139), Epidermophyton floccosum (19/139), Trichophyton mentagrophytes (9/139), Microsporum ferrigineum (4/139), Microsporum canis (4/139) and Microsporum gypseum (1/139). Scalp infections occurred in children and were due either to Microsporum canis or Microsporum ferrigineum. The organisms isolated in our study were either ubiquitous or common in the Asia-Pacific region indicating that certain dermatophytes are more prevalent in certain geographical regions.

Adolescent

Epidemiology of chronic paronychia in a skin hospital in Singapore.

A retrospective epidemiologic study of 110 patients with chronic paronychia (CP) showed a female-male ratio of 2.3:1, whereas the ratio of patients attending the same clinic was 1.1:1 (p less than 0.001). The peak age range of patients with CP (40-49 years) generally was greater than that of the general dermatologic patients (20-29 years). Seventy-seven percent of the patients with CP were "manual workers," of which 48% were homemakers. Chronic paronychia was more common on the right fingers than the left fingers. The most commonly affected fingers were the right thumb (62%), followed by the right middle finger (52%), left thumb (57.6%), and left middle finger (51.5%). Mechanical trauma appears to be an important predisposing factor in CP. Sixty-two percent of 68 patients who had nail fold smears had positive findings for budding yeast cells, suggestive of candidal infection. All of the six patients for whom nail fold bacterial cultures were performed had positive results for enteric flora.

Adult