Tertiary Dermatology Centre Research Articles

A restrospective review of fixed drug eruptions presenting at a tertiary dermatology centre in Singapore between 2008 and 2012

Fixed drug eruption (FDE) is a well-recognised localized cutaneous adverse drug reaction, characterized by its recurrence in the same sites upon re-exposure to the causative drug. We aimed to better understand the epidemiology, clinical features as well as the causative drugs of fixed drug eruptions in Singapore.

Long-term study of infliximab for psoriasis in daily practice: drug survival depends on combined treatment, obesity and infusion reactions.

Infiximab has been shown to be highly effective in phase III clinical trials, but limited information is available regarding drug survival and maintenance of efficacy beyond 1 year in real-life clinical setting. To analyse the efficacy and safety of infliximab in a large number of patients with a long follow-up and to identify clinical factors associated with long-term drug survival. A retrospective review of patients with moderate-to-severe psoriasis treated with infliximab from March 2004 to August 2012 at a tertiary dermatology centre was carried out. In total, 63 treatment courses with infliximab were administered to 56 patients. The mean duration of treatment was 31.6 months. The only significant positive predictor of drug survival was combination treatment [hazard ratio (HR) vs. monotherapy 2.90, 95% confidence interval (CI) 1.42–5.92]. Significant negative predictors of drug survival were obesity (HR 0.40, 95% CI 0.19–0.87) and infusion reactions (HR 0.40, 95% CI 0.19–0.87). Infusion reactions occurred in 13 (23%) of our patients and were a reason for discontinuation of treatment in 5. This retrospective review of a cohort of patients with moderate-to-severe psoriasis treated with infliximab in daily practice shows that the PASI75 response rates at 24 and 52 weeks of treatment are similar to those of the pivotal studies, but 37 courses of treatment (59%) had to be discontinued after a median of 12 months. The major cause for discontinuation was loss of response, in 18 cases. Combination treatment, obesity and infusion reactions were found to be predictors of drug survival.

Review of cases presented to a drug eruption clinic at a tertiary dermatology centre in Singapore

Review of cases presented to a drug eruption clinic at a tertiary dermatology centre in Singapore

The interferon-gamma release assay: Experience from a tertiary dermatology center in the tropics

The interferon-gamma release assay: Experience from a tertiary dermatology center in the tropics

A retrospective review of methotrexate‐induced hepatotoxicity among patients with psoriasis in a tertiary dermatology center in Malaysia

Methotrexate (MTX) is a common and efficacious systemic agent used for the treatment of moderate to severe psoriasis. Nevertheless, its use is associated with the risk of hepatotoxicity. This study was performed to study the association of MTX dose with regards to hepatotoxicity as evidenced by deranged transaminases. This was a retrospective review of patients with psoriasis on MTX from 2000 to 2009 at the outpatient dermatology clinic, University Malaya Medical Centre (UMMC). We analyzed patients' demography, serial laboratory investigations, liver ultrasounds, and liver biopsies of patients on MTX. Sixty-six of 710 (9.30%) patients with psoriasis were prescribed MTX throughout the 10-year period. Among them 57.6% developed deranged transaminases, with six requiring MTX withdrawal due to hepatotoxicity. The mean cumulative dose of MTX at the detection of liver enzyme derangement was 552.3 ± 596.1 mg. A high proportion of patients on MTX had deranged transaminases. However, the number of serious events was low. We concluded from this study that the use of MTX is relatively safe in patients with moderate to severe psoriasis.

Oral Aphthosis: Management Gaps and Recent Advances

Though oral aphthosis is common, it has a significant impact on the quality of life in the patients. It is the most common oral ulcerative condition encountered in clinical practice. This study describes the characteristics and patterns of oral aphthosis seen at a tertiary dermatological centre in Singapore, with emphasis in evaluating the management gaps and in identifying underlying systemic diseases and nutritional deficiencies. This is a retrospective review of medical records over a 10-year period between June 2000 and June 2010. Two hundred and thirteen patients were identified using the search terms 'oral ulcers', 'aphthous ulcers', 'oral aphthosis', and 'Behcet's disease'. Patients with Behcet's disease without oral ulcers and other diagnoses such as pemphigus vulgaris, lichen planus and herpes simplex were excluded. The remaining patients were evaluated with regard to demographic characteristics, characteristics of oral ulcers, associated connective tissue disorders and nutritional deficiencies, diagnostic tests results, treatment response as well as follow-up duration. One hundred and seventy-fi ve patients were included in this study. One hundred and one patients had recurrent oral aphthosis, with 77 having simple aphthosis and 24 having complex aphthosis. Fourteen patients (8%) fulfilled the International Study Criteria (ISG) for Behcet's disease, of which, 85.71% had complex aphthosis. The therapeutic ladder for such patients ranged from topical steroids and colchicine through to oral corticosteroids and/or dapsone therapy. Recurrent oral aphthosis is a niche condition in which dermatologists are well-poised to manage. This study demonstrates that a more definitive management and therapeutic algorithm for oral aphthosis are needed for better management patients in the future. In particular, complex aphthosis needs to be monitored for progression onto Behcet's disease.

Infliximab for the treatment of psoriasis in the U.K.: 9 years’ experience of infusion reactions at a single centre

Infliximab is an antitumour necrosis factor-α chimeric monoclonal antibody that is an established treatment for severe chronic plaque psoriasis. The recommended administration of a 2-h infusion followed by 2 h of monitoring is practised due to the potential occurrence of infusion reactions. However, accelerated infusions and shortened monitoring periods are used in patients with rheumatological disorders and inflammatory bowel disease without an increase in adverse events. To review the standard infliximab infusion protocol, the incidence of acute infusion reactions, the use of concomitant methotrexate and the clinical relevance of the 2-h postinfusion monitoring period. A retrospective case note and pharmacy database review of all infliximab infusions administered to patients with psoriasis at a tertiary dermatology centre was carried out. Fifty-nine consecutive patients received a total of 858 infliximab infusions (range 1-43 infusions per patient) between January 2001 and June 2010. The incidence of infusion reactions was 1.5%, affecting 16.9% of patients and occurring between the first and eleventh infusions. Mild, moderate and severe acute reactions occurred in 0.6% (n=5), 0.3% (n=3) and 0.3% (n=3) of infliximab infusions, respectively. Thirty-three patients (56%) received concomitant systemic treatments during part of or throughout the infliximab treatment, including 24 (41%) on methotrexate (5-20 mg weekly). The prevalence of infusion reactions in patients receiving infliximab alone was 27% compared with 4% in those receiving concomitant methotrexate (P=0.05). All infusion reactions were managed as per our trust protocol with only one infusion reaction occurring in the postinfusion period (10 min after infusion completion). The risk of infusion reactions in our cohort of patients was low, with the majority occurring early in the treatment cycle. Concomitant methotrexate may reduce this risk. A shortened postinfusion monitoring period can be safely considered.

Pinpoint papular polymorphous light eruption in Asian skin: a variant in darker‐skinned individuals

Polymorphous light eruption (PMLE) is the most common idiopathic but probably immunologic photodermatosis and has wide morphological variants. The photobiological features of all patients diagnosed with the pinpoint papular variant of PMLE at a tertiary dermatology centre in Singapore over a five-year period were retrospectively examined. Twenty-one patients were reviewed from 2003 to 2007. There were 11 (52.4%) Chinese, four (19%) Malays, five (23.8%) Indians and one (4%) Cambodian. 14 (66.7%) were males and seven (33.3%) were females. The face/neck (48%) and arms/forearms (95%) were most often affected. Nineteen (90.5%) had Fitzpatrick skin phototype IV and two (9.5%) had skin phototype V. Six (28.6%) had decreased minimal erythema dose (MED) to ultraviolet B (UVB) light only, one (4.8%) had decreased MED to ultraviolet A (UVA) light only and one had decreased MED to both UVA and UVB. Four patients had photoprovocation test done, of which three had positive testing to UVA and one had negative testing to both UVA and UVB. Two histological subtypes were found in our patients, one showing perivascular dermatitis and the other consistent with lichen nitidus. Our data suggest that pinpoint papular PMLE is not uncommon in darker-skinned individuals in our cohort.

HLA Antigens in Omani Psoriasis Vulgaris Patients.

To determine the frequency of different HLA-antigens in patients with plaque psoriasis in the Omani Arab population. Fifty four Omani patients clinically diagnosed with plaque psoriasis attending the dermatology outpatient clinic in Al-Nahdah Hospital (the tertiary dermatology centre in Oman) were selected for HLA studies. HLA-B52 was present in 20.4% of patients 11/54 and in 5% of controls without psoriasis 5/100. For the association p was <0.004 and the relative risk (RR) was 4.86. Psoriasis does not appear to be associated universally with the same HLA antigens. The association of HLA-B52 with plaque psoriasis in Omani patients compares with the HLA-Cw6, -Bw57 and -DR7 preponderance in most other ethnic groups.

Cutaneous sarcoidosis in Asians: a report of 25 patients from Singapore

Sarcoidosis is a systemic noncaseating granulomatous disorder of unknown origin involving multiple organ systems. There has been no report so far to describe the epidemiological pattern of cutaneous involvement in sarcoidosis in South-East Asia with diverse ethnic groups. A retrospective study examining the clinicopathological features of all patients diagnosed with sarcoidosis at a tertiary dermatology centre in Singapore from 1980 to 2003 was conducted. Cutaneous sarcoidosis was diagnosed in 25 patients: 13 were Indian, 11 were Chinese and one was Eurasian. Cutaneous manifestations included papules, nodules, plaques and scarring alopecia. Extracutaneous involvement of lymph nodes (four patients), lungs (eight patients) and eyes (two patients) was seen. Eight patients had abnormal chest radiographic findings. Histopathological examination of skin lesions revealed noncaseating, epithelioid granulomatous infiltration in the dermis without evidence of mycobacterial infection, deep fungal infection or polarizable birefringent material. Treatment modalities included corticosteroids, hydroxychloroquine, isotretinoin, methotrexate and surgical excision. Five patients had complete resolution of the cutaneous lesions. Cutaneous sarcoidosis is rare in Asia and indeed in Singapore. Extracutaneous involvement is not uncommon and a thorough clinical evaluation should be undertaken.

Behcet’s Disease: Experience in a Tertiary Rheumatology Centre in Singapore and a Review of the Literature

Introduction: The only reported study on Behcet’s disease (BD) in Singapore found that only 15% of 34 BD patients managed at a tertiary dermatology centre had arthritis and 6% had eye complications with no other systemic manifestations. The aim of our study was to characterise the clinical manifestations and outcome of patients with BD at a tertiary rheumatology centre in Singapore. Materials and Methods: The International Study Group (ISG) and the O’Duffy (OD) criteria were used. The demographics, manifestations and outcome of our patients with BD were recorded. Results: Thirty-seven patients were included in our study. Twenty-three (62.2%) satisfied both ISG and OD criteria. Fourteen (37.8%) did not fulfil the ISG criteria but fulfilled the OD criteria and of these 6 were the incomplete form and 8 the complete form. The male to female ratio was 1:1.1. The mean age of onset of disease was 32.7 years (range, 15 to 58 years). The commonest presentations were recurrent oral ulcers (37, 100%), genital ulcers (24, 64.9%), joint (21, 56.8%) and cutaneous manifestations (18, 48.6%). The most common systemic manifestations were arthritis (16, 43.2%), gastrointestinal manifestations (15, 40.5%) and uveitis (13, 35.1%). There were 2 cases of Neuro Behcet’s and 2 cases of venous thrombosis. Visual impairment from uveitis was the commonest cause of morbidity. There were no deaths in our series of BD. Conclusion: BD is a relatively rare rheumatologic condition in Singapore. However, because its systemic complications are not rare, early diagnosis and prompt treatment are essential.

Solar urticaria in Singapore: an uncommon photodermatosis seen in a tertiary dermatology center over a 10-year period.

Solar urticaria is an uncommon photodermatosis, characterized by the appearance of pruritic wheals after sun exposure. In this study, we examine the photobiological characteristics of solar urticaria in the heterogeneous group of Singaporean patients. The photobiological features of all patients treated for solar urticaria at a tertiary dermatology center in Singapore over a 10-year period were retrospectively examined. A total of 19 patients were diagnosed to have solar urticaria from 1993 to 2002. The mean age at diagnosis was 26 years, with a racial distribution of 17 (90%) Chinese, one (5%) Malay, and one (5%) Indian. Fifteen (79%) patients were males and four (21%) were females. The face/neck (47%) and arms/forearms (58%) were most often affected. Six (32%) patients had a history of atopy and two (11%) had dermographism. Fifteen (79%) patients had Fitzpatrick's skin type IV, three (16%) had skin type III and one (5%) patient had skin type V. The mean exposure time to wheal formation was 23 min. The action spectra of solar urticaria were visible light for 12 (63%) patients, ultraviolet (UV) A for one (5%), visible light and UVA for five (27%), and natural sunlight for one (5%) patient. All patients reported partial improvement with a combination of antihistamines and sunscreens as the main modality of treatment. Our data suggest that solar urticaria is an uncommon photodermatosis and a rare form of urticaria. Wheals were mostly elicited by visible light and/or UVA. A combination of antihistamines and sunscreens provided a useful form of therapy for patients with solar urticaria.

Balsam-related systemic contact dermatitis

Background: Positive patch tests to balsam of Peru (BOP) or fragrance mix (FM) suggest the possibility of systemic contact dermatitis from balsam-related foods and spices. Objective: This was a retrospective study to determine whether avoidance of balsam-related foods results in an improvement of dermatitis in these patients. Methods: A review of the records of all patients seen from July 1 to Dec 31, 1998 with positive patch tests to BOP, FM, cinnamic aldehyde, and balsam of tolu was performed 9 to 14 months after their evaluation in a tertiary dermatology center. All patients were contacted via telephone to assess the status of their dermatitis and whether they were able to note any specific balsam-related food allergies. Results: A total of 75 patients were identified, and 71 could be contacted. Fourteen were only allergic to BOP or FM on testing; 31 were positive to BOP/FM and other allergens with presumed relevance to BOP/FM; 26 were positive to BOP/FM and others with other allergens felt to be responsible for the dermatitis and were not placed on a BOP diet. Excluding this last group, 21 of 45 (47%) had complete or significant improvement that they related to dietary modification. Ten did not modify their diet, with 8 reporting no improvement. Eight improved with fragrance or other allergen avoidance only, and 6 modified their diet unsuccessfully. Most commonly implicated foods included tomatoes, citrus, and spices. Conclusion: Almost half of the subjects with positive patch tests to BOP or FM who followed a BOP reduction diet reported significant to complete improvement of their dermatitis. (J Am Acad Dermatol 2001;45:377-81.)

Occupational allergic contact dermatitis in Singapore

Singapore has a resident population of 3 000 000 and a workforce of 1 780 000. Most are employed in manufacturing, services and commerce (245 000). From 1996 to 1998, 3472 cases were notified to the Ministry of Manpower and confirmed as occupational diseases. Noise-induced hearing loss accounted for 82% of cases, while only 11% of cases were industrial dermatitis. Occupational allergic contact dermatitis was not common, comprising approximately one third of the 369 cases of industrial dermatitis that were notified. However, we believe that the majority of cases are not notified to the authorities. The main occupational contact allergens were chromates, nickel, rubber chemicals, cutting fluids and resins. Most affected workers were from the construction, electronics and metalworking industries. Case series of occupational dermatoses among electronics and metal workers have been published. Of the cases of occupational dermatoses among electronics workers seen at a tertiary dermatological centre, 41% of 149 had allergic contact dermatitis (ACD). The commonest allergens were nickel, resins and rubber chemicals. In another case series of 252 metalworkers seen at the same dermatological centre, 23% suffered from ACD. The common allergens were metals and cutting fluids. Besides the common causes of ACD, unusual allergens have also been described. One example is ACD to grasses, which is seen mainly among military personnel. Population studies have been conducted in several industries. A survey of 2567 electronics workers revealed a 2% point prevalence of ACD. Of the occupationally relevant cases, 46 were nickel sensitive, 7 reacted to colophony, and 1 case to epoxy resin. A study of 272 prefabrication construction workers showed a 14% prevalence rate of occupational dermatitis. Of the 38 cases, 42% were ACD to chromates and rubber chemicals. Occupational ACD in Singapore is not as uncommon as the reported statistics suggest. Population-based reports, which overcome the problem of under-notification, show that the prevalence is variable in different industries.

Characteristics of bacterial skin infections in children compared to adults at a tertiary dermatologic center

Bacterial skin infections in children and adults are caused by different organisms with different antimicrobial susceptibility. A comparative retrospective study was carried out on 233 adults and 53 children with bacterial skin infections. Skin swab cultures and sensitivity tests were performed using standard methods. Statistical analysis was performed using the Pearson chi-squared and Fisher tests. A P value of < 0.05 was considered to be significant. Primary and secondary skin infections occurred in equal proportions in children, whereas secondary skin infections were more common in adults (70.8%). Staphylococcus aureus was the main cause of skin infections, particularly in children (72.6%). S. aureus in children and adults was highly susceptible to cloxacillin, cephalexin, chloramphenicol, neomycin, cotrimoxazole, and clindamycin, moderately susceptible to erythromycin, and insensitive to tetracycline, ampicillin, and penicillin. It is important to monitor the trends of bacterial infections and their antibiotic susceptibility as this can assist medical practitioners in their choice of antimicrobial therapy. Such monitoring will also help to detect the emergence of resistant bacterial strains and caution us to take care in the use of certain drugs.