Variation in allergen content over time of acrylates/methacrylates in patch test preparations.

BACKGROUND: Acrylates/methacrylates are volatile substances. There might be a gradual decrease in acrylate/methacrylate allergen content over time in patch test preparations but this has not yet been documented. OBJECTIVES: To determine the allergen content of acrylates/methacrylates in patch test preparations over time under different storage conditions. METHODS: Five acrylate/methacrylate allergens [2-hydroxyethyl methacrylate (2-HEMA), methyl methacrylate (MMA), ethylene glycol dimethacrylate (EGDMA), triethylene glycol diacrylate (TREGDA) and 2-hydroxypropyl acrylate (2-HPA)] in syringes and IQ™ chambers (Chemotechnique Diagnostics, Vellinge, Sweden) were analysed using gel permeation chromatography and high-performance liquid chromatography to measure the allergen content over time in samples stored in the freezer, refrigerator and under room temperature. RESULTS: The concentration of allergens in syringes decreased with time. Those stored at room temperature had the fastest rate of decrease, followed by those in the refrigerator and freezer. In most cases, in syringes or IQ™ chambers under all storage conditions, the MMA decreased most rapidly, followed by 2-HPA, 2-HEMA, EGDMA and TREGDA. The allergens in the IQ™ chambers rapidly disappeared, with almost all samples reaching nondetectable levels by day 8. MMA was the first to reach a nondetectable level--at day 2. CONCLUSIONS: Acrylate/methacrylate allergens are lost rapidly from IQ™ chambers especially if stored at room temperature. Allergens in syringes remain above 80% of their initial concentrations for longer periods compared with IQ™ chambers. In syringes and IQ™ chambers there is a slower rate of decrease in concentration when the storage temperature is lower. Allergens should be stored refrigerated, replaced regularly, and freshly applied on to test patches on the day of use.

A randomized double-blind controlled trial to compare a triclosan-containing emollient with vehicle for the treatment of atopic dermatitis.

The use of topical antiseptics in the treatment of atopic dermatitis (AD) has previously been explored. However, no triclosan-containing leave-on emollient has been evaluated previously, to our knowledge. The aims of this study were to assess the safety and efficacy of an emollient containing triclosan compared with the emollient alone (vehicle) for the treatment of AD. Eligible patients with mild to moderate AD were randomized to receive either the study cream or vehicle. All patients also received a low-potency corticosteroid cream to use during the treatment phase of the study if necessary. Patients were assessed for severity according to the SCORing Atopic Dermatitis (SCORAD) Index, amount of corticosteroid used, patient assessment of cream, and adverse events (AEs). In total, 60 patients received either the study cream or vehicle, and an intention-to-treat analysis was performed. At day 14, there was a significant decrease in SCORAD from baseline for the study cream compared with vehicle (P < 0.05). At day 27, although there was an improved mean reduction from baseline, this was no longer significant (P > 0.05). Only four patients had mild treatment-related AEs. The mean total amount of topical steroid applied by the patients using the study was significantly lower than that used by controls (P = 0.40). Triclosan-containing leave-on emollient was safe and highly acceptable to patients. However, the overall benefit on day 27 was not significant. Nevertheless, the amount of topical steroid used by patients was significantly less with the study cream than with the vehicle, thus further studies are needed to confirm its steroid-sparing effect.

Study on the efficacy of ELA-Max (4% liposomal lidocaine) compared with EMLA cream (eutectic mixture of local anesthetics) using thermosensory threshold analysis in adult volunteers.

BACKGROUND: ELA-Max and EMLA cream are topical anesthetics that have been shown to have similar anesthetic efficacy in previous studies. OBJECTIVE: To evaluate the analgesic efficacy of ELA-Max in comparison with EMLA cream using a novel method of thermosensory threshold analysis. METHODS: A thermosensory analyzer was used to assess warmth- and heat-induced pain thresholds. RESULTS: No statistically significant difference was found in pain thresholds using either formulation. However, EMLA cream increased the heat-induced pain threshold to a greater extent than ELA-Max. Thermosensory measurement and analysis was well tolerated and no adverse events were encountered. CONCLUSIONS: EMLA cream may be superior to ELA-Max for heat-induced pain. This study suggests that thermosensory measurement may be another suitable tool for future topical anesthetic efficacy studies.

Itch characteristics in Chinese patients with atopic dermatitis using a new questionnaire for the assessment of pruritus.

BACKGROUND: Although pruritus is the predominant and commonest feature of atopic dermatitis, its clinical characteristics have not been explored. OBJECTIVE: To characterize the clinical pattern and sensory and affective dimensions of the itch experience utilizing a comprehensive itch questionnaire. METHODS: A structured itch questionnaire based on the McGill pain questionnaire was given to 102 Chinese patients with known atopic dermatitis. RESULTS: There were 100 patients with atopic dermatitis who fully filled the questionnaire. In 87% of the patients pruritus appeared on a daily basis. It had a prolonged duration (mean duration 10.7 7.3 years). It involved all body areas mostly in the lower limbs (83%), flexures (76%), upper limbs (71%) and neck (65%). Itch intensity during its peak was nearly twice higher than the itch of a mosquito bite. Itching was most frequent at night (65%), and 84% of patients reported of difficulty falling asleep. Daily life activities which increased the severity of itch were sweat in 96%, dryness in 71%, stress in 71% and physical effort in 73%. The major factors which were found to reduce the intensity of pruritus included: bathing with cold water in 55% and cold ambient environment in 56%. Associated symptoms were heat sensation (51%), sweating (40%) and pain in the pruritic area (45%). The various anti-pruritic therapies had limited long-term effect. The pruritus was bothersome (52%) and a major distress to the patient. The affective score correlated to itch intensity during its peak (r = 0.4, P < 0.001). CONCLUSIONS: The study provided a detailed description of pruritus in atopic dermatitis with new data on affective and sensory dimensions and associated symptoms. The questionnaire was found to be a useful tool in characterization of itch.

Pemphigus vulgaris following varicella infection.

We describe a 26-year-old Indian man who presented with chickenpox and subsequently developed pemphigus vulgaris 17 days after initial resolution of lesions. The mechanism of progression from one disease to the other is postulated to be that of epitope spreading or molecular mimicry.

Comparison of allergic contact dermatitis cases in the private and subsidized clinics in the National Skin Centre, Singapore.

INTRODUCTION: This is an epidemiologic study to compare allergic contact dermatitis patients in the private and subsidized clinics. PATIENTS AND METHODS: All patients diagnosed to have allergic contact dermatitis in the National Skin Centre from January 1999 to June 1999 were studied retrospectively. RESULTS: More private patients were evaluated for allergic contact dermatitis than subsidized patients in the study period (138 vs. 99). The female-to-male ratio in the paying clinics was greater than in the subsidized clinics (3:1 vs. 1:1). The mean age was the same for both groups i.e., 40 years. There was a greater proportion of unskilled workers attending the subsidized clinic (24.2% vs. 5.4%). The mean duration of rash before evaluation was longer for paying patients than for subsidized patients (31 vs. 22 months), but this was not statistically significant. A significant proportion of the patients had a history of atopic disease and endogenous dermatitis. The most frequent sites for allergic contact dermatitis were the face, hands and the exposed areas of the limbs. The most common allergens were nickel, cobalt and fragrance in the paying patients; and nickel, chromate and fragrance in the subsidized patients. CONCLUSION: More female patients with allergic contact dermatitis and more atopic patients were seen in the private clinics. The forearms, fingers, feet and ears were more commonly affected in the subsidized patients.

Comparative study of pemphigus vulgaris and pemphigus foliaceus in Singapore.

This is a retrospective study of all patients diagnosed to have pemphigus in our centre over a 3 year period. The case records of all patients with pemphigus from January 1995 to December 1997 were analysed. Fifty patients were diagnosed to have pemphigus during the study period. The diagnoses were pemphigus vulgaris in 31 patients, pemphigus foliaceus in 16, paraneoplastic pemphigus in two and IgA pemphigus in one. The average titre of anti-intercellular antibodies in patients with pemphigus vulgaris (1:96) was higher than the titre in patients with pemphigus foliaceus (1:69). The average initial dose of prednisolone required for disease control in patients with pemphigus vulgaris (62 mg/day) was significantly higher than that required for patients with pemphigus foliaceus (44 mg/day). In our study population, pemphigus vulgaris is a more severe and chronic disease than pemphigus foliaceus, as reflected in the higher titre of anti-intercellular antibodies, higher dose of systemic corticosteroids required for control of the disease, the longer duration to achieve complete remission and longer follow-up period.

Occupational skin diseases in national servicemen and military personnel in Singapore, 1989-1999.

This is a study of occupational skin disease among military personnel and conscripts in Singapore. All military personnel and conscripts diagnosed with occupational dermatoses in the National Skin Centre, Singapore, between 1989-1999 were studied retrospectively. Conscripts and regulars comprised 7.3% of all occupational skin disease patients seen. All were male, with a mean age of 23 years. Irritant contact dermatitis was more common than allergic contact dermatitis, by 4.4:1. The most common vocations associated with occupational skin diseases are those involving vehicle repairs and maintenance (48%) and food handling (19%). The most common irritants were oil/grease (66%), wet work (23%) and solvents (18%). The most common allergens were food (40%) and chromates (20%). Military personnel and conscripts make up a significant proportion of occupational skin disease patients seen in Singapore.

Tetracycline and nicotinamide for the treatment of bullous pemphigoid: our experience in Singapore.

AIM OF STUDY: To study the efficacy of tetracycline (or doxycycline) and nicotinamide in the treatment of less extensive bullous pemphigoid. METHODS: An open trial of 11 patients with bullous pemphigoid. Treatment was initiated with tetracycline 1.5-2 g/day and nicotinamide 1.5-2 g/day and gradually tapered down. Doxycycline was substituted for tetracycline in patients who could not tolerate tetracycline due to gastrointestinal side effects or headache. RESULTS: 6 out of 11 patients achieved complete response (> 90% decrease in lesions) while another 2 had partial response (50-90% decrease in lesions). CONCLUSION: Tetracycline/doxycycline and nicotinamide is a useful alternative treatment for localized bullous pemphigoid, especially in those whose concurrent medical illnesses preclude the use of systemic corticosteroids.

Epidemiology of occupational skin disease in Singapore 1989-1998.

This is an epidemiologic study of occupational skin disease in Singapore. All patients diagnosed with occupational dermatoses in the National Skin Centre, Singapore, over the 10-year period 1989-1998 were studied retrospectively. Irritant contact dermatitis was found to be more common than allergic contact dermatitis. The major sources of occupational dermatitis in Singapore were the metal/engineering, building/construction, electrical/electronics and transport industries. The main irritants were detergents/wet work, solvent and oil/grease. The main allergens were chromate, rubber chemicals and nickel. We concluded that the main sources of occupational skin disease and main allergens in Singapore had remained the same compared to a similar study of occupational skin diseases in 1984-85. Weak irritants are still the predominant causes of occupational irritant contact dermatitis, though the main irritants have changed compared to the previous study, where cutting fluids, cement and solvent were the most common irritants.

An unusual case of cutaneous vasculitis.

INTRODUCTION: We report an unusual case of a patient with clinical and histological features of cutaneous vasculitis. CASE PICTURE: A middle-aged Chinese male presented with livedo reticularis and digital gangrene without visceral involvement. Skin biopsy showed features suggestive of cutaneous vasculitis. Repeated testing for anticardiolipin antibody was negative. TREATMENT: He was treated with two courses of intravenous prostacyclin and pulsed with one course of intravenous methylprednisolone. He was also put on oral prednisolone, pentoxifylline, aspirin, nifedipine and colchicine in addition to symptomatic therapy. OUTCOME: There was gradual improvement of his toe discolouration and relief of pain. CONCLUSIONS: This is an interesting case of cutaneous vasculitis, which has features of polyarteritis nodosa and the antiphospholipid syndrome, who responded well to intravenous prostacyclin, steroids, pentoxifylline, aspirin, nifedipine and colchicine.

A case of recurrent disseminated granuloma annulare.

We present an 11-year-old boy who developed multiple pruritic, skin-coloured papules on his forehead, which subsequently spread to his trunk and limbs over a period of 6 months. Histology revealed granuloma annulare. The lesions underwent spontaneous regression over the next five years. He presented again when he was 18 years old, with a spontaneous eruption of multiple lesions on the trunk and the limbs 2 years after complete clinical remission from the first attack. A punch biopsy performed at this presentation revealed granuloma annulare again. No treatment was given and he is still being followed up. The tendency for spontaneous resolution of granuloma annulare is well recognised. Recurrent localized lesions often disappeared more rapidly than the original ones. Recurrence of disseminated GA, to our knowledge, has not been reported before.