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Biomedical subjects

S N Tham

Publications and source records attributed to S N Tham.

At least 19 recordsLinked to original sources
PubMed1997

The profile and outcome of pustular psoriasis in Singapore: a report of 28 cases.

BACKGROUND: Pustular psoriasis is a rare form of psoriasis that can be divided into generalized and localized forms. The aim of this study is to describe the patient profile and outcome of pustular psoriasis seen at a tertiary referral skin center in a tropical country. METHODS: The records of all patients with pustular psoriasis during the 4 years from 1989 to 1993 were reviewed. Diagnostic criteria for selection included at least one episode of either generalized or localized macroscopic noninfective pustulation. RESULTS: There were 28 patients with pustular psoriasis, with an age range of 4-77 years. Nineteen patients had generalized pustular psoriasis: Von Zumbusch (seven), annular form (two), juvenile form (six), pustular psoriasis of pregnancy (one), and the localized form of generalized pustular psoriasis (three). Nine patients had localized pustular psoriasis: palmoplantar pustulosis (five) and acrodermatitis continua (four). Patients with the acute Von Zumbusch pattern had recalcitrant disease with multiple flares and significant morbidity and mortality. Patients with the annular form had a subacute onset and a chronic course. In patients with the juvenile form of generalized pustular psoriasis, two patterns could be recognized: Zumbusch form (four) and annular form (two). Despite significant morbidity, each of our young patients had a relatively benign course with no deaths and an excellent response to etretinate therapy. Our nine patients with localized pustular psoriasis all had a chronic course: the average duration of disease was 6 years for patients with palmoplantar pustulosis and 12 years for patients with acrodermatitis continua. CONCLUSIONS: The pattern of pustular psoriasis seen in Singapore is similar to that reported in the Western literature. Using these categories we can provide guidelines for treatment and prognosis.

Adolescent↗
PubMed1997

Glycolic acid peels in the treatment of melasma among Asian women.

BACKGROUND: Melasma is a common disorder of facial hyperpigmentation among Asian women. Many modalities of treatment are available but none is satisfactory. OBJECTIVE: This study was undertaken to see if glycolic acid peels are effective and safe in the treatment of melasma and fine facial wrinkling. METHODS: Ten Asian women with moderate to severe melasma were recruited into the study. The women had twice daily applications of a cream containing 10% glycolic acid and 2% hydroquinone (Neostrata AHA Age Spot and Skin Lightening Gel) to both sides of the face, and glycolic acid peels every 3 weeks (20-70%) to one-half of the face using Neostrata Skin Rejuvenation System. All patients had to use a sunblock (SPF 15%). At regular intervals and at the end of 26 weeks (or after eight peels) the degree of improvement of pigmentation and fine facial wrinkling on each side of the face were assessed. Any skin irritation or side effects were also noted. Assessment was by an independent dermatologist, the patients themselves, and the use of the Munsell color chart and photographs. The nonparametric Wilcoxon Rank-Sum test was used for statistical analysis. RESULTS: The melasma and fine facial wrinkling improved on both sides of the face. The side that received glycolic acid peels did better but the results were not statistically significant (P > 0.059). CONCLUSION: A cream containing 10% glycolic acid and 2% hydroquinone (Neostrata AHA Age Spot and Skin Lightening Gel) improved melasma and fine facial wrinkling in Asian women. In combination with glycolic acid peels at 3-week intervals the lightening of melasma is subjectively much better. This improvement does not reach statistical significance and the sample size is small (n = 10).

Administration, Topical↗
PubMed1997

Patterns of psoriatic arthritis in Orientals.

OBJECTIVE: To determine the clinical features of psoriatic arthritis (PsA) in a multiethnic Oriental population and to study the effect of ethnicity on disease patterns. METHODS: A retrospective study of 80 patients with PsA seen at either a rheumatology or dermatology referral center. Patients and case records were reviewed and data abstracted according to a standard protocol. Eighty consecutive patients with psoriasis without PsA seen at the dermatology center were recruited as controls. RESULTS: Asymmetric polyarthritis developing in the 4th decade with an equal male to female ratio was the commonest pattern of arthritis among Chinese, Indians, and Malays. Clinically apparent lumbar spondylitis was significantly more common in Indians than Chinese (10/11 vs 11/20, respectively; p = 0.046), although the prevalence of lumbar spondylitis was similar in all ethnic groups. Eighty-nine percent of subjects required nonsteroidal antiinflammatory drugs and 51% required disease modifying antirheumatic drugs at some time for control of joint disease. PsA was significantly more common among Indians compared to the ethnic distribution of the Singapore population (p < 0.000001). Multiple logistic regression identified Indian ethnicity as a risk factor for the development of PsA (OR 2.39, 95% confidence interval 1.02 to 5.60). CONCLUSION: The commonest pattern of PsA in all ethnic groups was asymmetric polyarthritis. Ethnicity affected the development and presentation of PsA in our series: Indians with psoriasis had double the risk of developing PsA compared to Chinese with psoriasis, and lumbar spondylitis when present in Chinese subjects was asymptomatic in 45%, being detectable only on radiological examination.

Adult↗
PubMed1996

Photodermatoses in a Singapore skin referral centre.

The inducing or exacerbating effect of sunlight on skin diseases is often not appreciated in tropical countries, perhaps because of the perennial presence of sunlight, and a retrospective review of photodermatoses seen in a referral skin clinic was therefore carried out. The photodermatoses seen were secondary photoaggravation of primary skin diseases (32.2%), systemic drug photosensitivity (11.3%), polymorphic light eruption (13%), chronic actinic dermatitis (5.3%), solar urticaria (5.3%), actinic prurigo (4%), photoallergic contact dermatitis (2.6%), porphyria (1.3%) and xeroderma pigmentosum (1.3%). Compared with the results of Western studies, there were more photoaggravated underlying skin diseases and systemic drug photosensitivity, and fewer idiopathic photodermatoses and photoallergic contact dermatitis; the common photoallergens were chlorpromazine, promethazine and musk ambrette, very similar to those seen in the West.

Adolescent↗
PubMed1996

Localized vulvar syringomas--an unusual cause of pruritus vulvae.

Genital syringomas are rare and usually asymptomatic. We report 2 young women who presented with pruritus vulvae. Examination revealed multiple bilateral skin-coloured papules over the labia majora. Histology showed syringoma. Syringomas should be considered in the differential diagnosis of pruritic papular lesions of the vulva.

Adult↗
PubMed1996

A report of 31 cases of porokeratosis at the National Skin Centre.

Porokeratosis is a well-recognised disorder of keratinization with distinctive clinical features and histological hallmark of cornoid lamella. There are at least 4 different clinical variants, with malignant transformation reported in almost all types of porokeratosis. This is a retrospective study on all cases of porokeratosis seen at the National Skin Centre, Singapore from 1990 to 1993. There was a total of 31 patients diagnosed to have porokeratosis during the study period. They can be classified into 4 main clinical variants: (1) disseminated superficial actinic porokeratosis (41.9%), (2) classical porokeratosis of Mibelli (35.5%), (3) porokeratosis palmaris, plantaris et disseminatum (9.7%), and (4) linear porokeratosis (12.9%). Our typical patient is in his/her early forties, who noticed asymptomatic porokeratotis lesion on sun-exposed skin. Various treatment modalities were used, with no one method being more superior to another. None of our patients had malignant transformation of pre-existing skin lesions during the short follow-up period from less than one year to three years. Patients should be advised to avoid excessive sunlight, to use sunscreen and go for periodic examination by a dermatologist with a view to close skin malignancy surveillance.

Adolescent↗
PubMed1995

Skin cancers at Tertiary Referral Skin Hospital in Singapore.

BACKGROUND: Skin cancer is the seventh most common cancer in Singapore. This study was performed to determine the pattern of skin cancers seen in a tertiary referral skin hospital. METHODS: Histologically confirmed skin cancers, seen between 1980 and 1991, were analyzed according to age, sex, race, site, and presence/absence of preexisting skin conditions. RESULTS: Of a total of 520 patients, the commonest skin cancer was basal cell carcinoma (BCC) (36.5%), followed by squamous cell carcinoma (SCC) (24.4%), Bowen's disease (16.7%), and mycosis fungoides (9.0%). Malignant melanomas (2.7%) were rare. The sharp increase (26.2%) in BCC in the recent 3 years was largely contributed by a fivefold increase of non-resident Caucasian patients with BCC. All types of skin cancers were more common in Chinese (78.1%) and less frequent in the more pigmented races (9.4%). The men to women ratio was 1.72:1. The peak age distribution was in the 51-70-year group, with the exception of mycosis fungoides (31-50 years). The commonest site involved in BCC was the head and neck (67.0%) and in Bowen's disease the trunk (33.3%). Squamous cell carcinoma was found on the head and neck and the lower extremities with equal frequency (29.3%) and 46.2% of all SCC on the lower extremities occurred in leprosy patients with chronic trophic ulcers. Of patients with Bowen's disease involving the nonsunexposed parts (trunk and upper extremities), 42.6% had probable arsenic exposure evident either from the history or clinical examination. Malignant melanomas were commonly located on the foot (71.4%). CONCLUSIONS: The commonest skin cancers seen were BCC, SCC, Bowen's disease, and mycosis fungoides. There were differences in the site distribution of SCC, Bowen's disease, and malignant melanomas in our study when compared to studies in Caucasians.

Adult↗
PubMed1995

UV-protective sunglasses for UVA irradiation protection.

BACKGROUND: Eye protection with UVA-blocking solar shields is recommended on the day of PUVA treatment and the following day for our patients; however, many patients found this eyewear cosmetically unacceptable. METHOD: We investigated 34 pairs of sunglasses to determine their suitability for providing adequate protection. The method used was modified from the technique used by Moseley et al. in 1988. RESULTS: We found that 21 (61.8%) of the 34 pairs of sunglasses and only 9 (53%) of the 17 pairs of sunglasses used by our patients were "satisfactory." Expensive brands and polarizing sunglasses do not guarantee optimal UVA protection. CONCLUSION: We recommend that all patients should use wrap-around solar shields for optimal eye-protection, while undergoing PUVA treatment. The availability of more cosmetically acceptable glasses will encourage better patients' compliance to protect their eyes with optical aids.

Eye↗
PubMed1995

A questionnaire-based survey of patients' knowledge of psoriasis at the National Skin Centre.

Psoriasis is a chronic disease, which while potentially controllable, cannot be cured. Treatment is long term and requires continuous effort by the patient. Patient education is important for a chronic disease like psoriasis and this involves acquiring knowledge about the disease. With knowledge gained, the patient will be better able to cope, improve decision-making and comply with treatment. The aim was to determine the level of knowledge of psoriasis among four groups of patients attending the National Skin Centre. The study population consisted of 120 patients divided into four groups with 30 patients each from the general clinic, psoriasis clinic, private clinic and phototherapy clinic. The patients were asked to fill up a questionnaire. For those who were Chinese educated, a Mandarin translation of the questionnaire was made. The patients' age ranged from 13 to 83 years with a mean of 39 years. The mean duration of psoriasis was 9 years. Patients from the phototherapy clinic scored significantly higher than patients from the other clinics. There were, however, gaps in the knowledge of psoriasis among the various groups. No correlation was noted between age, sex, duration of psoriasis, number of consultations or phototherapy session with correct scores to the questionnaire. The most common treatment prescribed for the general and private clinics was a combination of topical steroids and tar (67% and 44% respectively). For the psoriasis clinic, the most common treatment prescribed was methotrexate (60%). For the phototherapy clinic, the most common modality used was ultraviolet B light (60%). Education is important in the overall treatment of psoriasis patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

A comparative study of calcipotriol ointment and tar in chronic plaque psoriasis.

The antipsoriatic efficacy, tolerability and safety of calcipotriol ointment was compared with tar in a prospective, right/left randomized, investigator-blinded controlled study. Calcipotriol ointment 50 micrograms/g twice daily was applied to one-half of the body. On the opposite side, white soft paraffin was applied in the morning, and coal tar solution BP 15% v/w in aqueous cream in the evening. Thirty patients with stable chronic plaque-type psoriasis were recruited. Assessments were made at 2, 4 and 6 weeks. Three patients were withdrawn from the study. A decrease in PASI score was seen on both sides at 2, 4 and 6 weeks. The differences from baseline between the two treatments were statistically significant in favour of calcipotriol. Improvement with calcipotriol was rapid in the first 2 weeks of treatment. With tar, significant improvement occurred only after 4 weeks of treatment. The differences in the scores for erythema, induration and desquamation from baseline between the two treatments were also statistically significantly in favour of calcipotriol at all evaluation points. Seven patients developed irritation on the calcipotriol-treated side, but there were no adverse effects on the tar-treated side. In two patients, itching associated with psoriasis was reduced by the calcipotriol. Although the mean serum calcium and phosphate levels remained within the normal ranges after 6 weeks' treatment, there were significant changes in their values compared with baseline.

Administration, Cutaneous↗
PubMed1994

Isotretinoin therapy in acne vulgaris: a 10-year retrospective study in Singapore.

BACKGROUND: The use of isotretinoin, a first generation synthetic retinoid, in the treatment of patients with severe acne vulgaris was a major therapeutic advance in dermatology. This 10-year retrospective study reviews the effectiveness of isotretinoin in patients with acne vulgaris seen in a skin clinic in Singapore. METHODS: The case records of 250 cases of severe inflammatory and nodulocystic acne treated with isotretinoin were analyzed with reference to the demographic data, response to isotretinoin, dosage and cost of isotretinoin used, adverse effects, clinical follow-up, and relapse. RESULTS: Two hundred and fifty patients, 171 men (68.4%) and 79 women (31.6%), with different types and grades of acne vulgaris were studied. The dose of isotretinoin used ranged from 0.33 to 1.0 mg/kg/day (median 0.5 mg/kg/day) for a period ranging from 1 to 12 months (median 4 months). Response was excellent in 127 (50.8%) patients, good in 86 (34.4%), fair in 30 (12.0%) and poor in 7 (2.8%). Relapse occurred in 14 (5.6%) patients over a 6-month follow-up period. Adverse effects were noted in 140 (56.0%) patients and were mild in most cases. Eighteen (7.2%) patients had to discontinue the drug due to significant side effects. CONCLUSION: This study confirms that isotretinoin is very effective for severe acne, and complete remission can be induced in more than 90% of cases even with lower dosage regimens. Significant clinical improvement can be achieved with the use of lower doses (mean 0.5 mg/kg/day) for an average of 4 months of treatment with lower risk of adverse effects.

Acne Vulgaris↗
PubMed1994

Methotrexate in the treatment of psoriasis at the National Skin Centre, Singapore.

In the last 30 years, methotrexate has been used for treating psoriasis, rheumatoid arthritis and other inflammatory disorders. Much has been learned about its beneficial and adverse effects. Long-term use produces different effects from short-term use. This study was undertaken to study the long-term use of methotrexate in our local population. It is a retrospective study where the case reports of 72 psoriatic patients on methotrexate were analysed for its use, side effects, the monitoring of side effects and its efficacy. Our study showed that methotrexate was effective in 61 (86.0%) patients, had some side effects in 10 (14.2%) patients and was relatively safe. It also helped psoriatic arthropathy. However, adequate and close monitoring is required to prevent liver fibrosis and cirrhosis.

Adult↗
PubMed1993

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↗
PubMed1993

Pachydermoperiostosis (idiopathic hypertrophic osteoarthropathy)--a case report and review.

We report a Chinese patient with the complete form of pachydermoperiostosis. He presented with typical features consisting of palmoplantar hyperhidrosis, clubbing with spade-like enlargement of the hands and feet, cutis verticis gyrata, thickening and furrowing of the facial and forehead skin, and irregular thickening of the cortical bone with subperiosteal new bone formation involving the radii, ulnae. tibiae and fibulae. Classically, pachydermoperiostosis is characterised by a triad of finger clubbing, periosteal new bone formation, skin and soft tissue changes, giving an acromaegaloid look. Although rare, it is important to recognise this condition as misdiagnosis may subject the patient to unnecessary investigations and worry. The typical features and the self-limiting nature of this entity are emphasised.

Adult↗
PubMed1993

Immunological characterisation of the lichen planus infiltrate using monoclonal antibodies.

The immunological typing of cell populations in the skin biopsies of 20 cases of histologically proven lichen planus was done using monoclonal antibodies. The Avidin-Biotin-Complex immunoperoxidase technique was used. A predominance of T-helper/inducer cells in the dermal infiltrate was observed by a semiquantitative analysis. T-suppressor/cytotoxic cells and Langerhans cells were increased compared to eczema lesions. A comparison of the staining of Langerhans cells using monoclonal antibodies and the S100 protein stain showed that more Langerhans cells could be identified with the CD1 monoclonal antibody. The type of infiltrate did not correlate with the duration of disease. Direct immunofluorescence staining demonstrated fibrinogen at the dermo-epidermal junction and/or colloid bodies in the upper dermis. The immunophenotyping and immunofluorescence pattern in local cases of lichen planus are similar to previous reports from other countries. An interesting finding was the unexplained disproportionate predominance of Indians in the study cohort.

Adolescent↗
PubMed1992

Primary tuberculous chancre in a renal transplant patient.

A case of primary tuberculous chancre of the vulva is reported. Although a tuberculous infection in an immunocompromised patient is not uncommon, this is the first report of a primary tuberculous infection on the external genitalia in such a patient. The source of infection in this patient could not be determined.

Chancre↗