A three-year photopatch study in Thailand.

Photopatch testing was performed on 274 patients who had history of photosensitivity at the Institute of Dermatology Thailand from 1987 through 1989. A total of 92 positive photocontact reactions and 71 positive contact reactions were seen. The most frequent positive photopatch test reactions were to sulfanilamide (18.2%) followed by Jadit (4.4%) chlorpromazine (3.6%) promethazine (3.6%) and fenticlor (3.2%). The most common photodermatoses was polymorphous light eruption (60.9%). Photocontact dermatitis was established in 28 patients (10.2%) while other skin diseases aggravated by sunlight were seen in 47 patients (17.2%).     

Adult-onset actinic prurigo in Thailand

BACKGROUND: Actinic prurigo (AP) is one of the rare idiopathic photodermatosis. It is said to be a familial disease and is usually seen in certain specific geographical areas. The adult-onset type of AP is reported less frequently in the Asian population and has never been reported in Thailand. METHODS: The study population comprised 30 patients. Demographic data were collected. Photo-tests and photo provocation tests for UVA, UVB and visible light were carried out on non-exposed skin. The other investigations included antinuclear antibody, anti-HIV antibody and urine porphyrin level. Histopathology studies were also carried out. RESULTS: There were 18 males and 12 females. The mean age of onset was 36.86 years. The duration of disease was from 1 month to 20 years. Forearms (27 patients) were the most frequently affected site. Other screening tests showed negative results. Five patients had abnormal MED to UVA and one patient had abnormal MED to UVA as well as UVB. Photo provocation tests showed positive responses to both UVA and UVB in 12 cases (40%), a positive response to UVA in 11 cases (37%), a positive response to UVB alone in four cases (13.3%) and a normal response in three patients (10%). None of the patients had a positive response to visible light. Skin biopsies were performed on nodular lesions in 23 cases. Histopathology from these 23 cases showed hyperkeratosis ortho- or parakeratosis and acanthosis in 20 of the 23 cases. CONCLUSIONS: Adult-onset AP in our country may have different geographic and racial distribution from previous reports or may be the tropical variant as described by Tham et al. It may not be an uncommon disease in our country, if there is increased awareness of this disease. Only 16.6% of patients had reduced MED. Photo provocation tests were positive in 90% of cases. Most of the positive wavelengths were UVA or both UVA and UVB. Therefore, photo provocation tests should be performed in cases suspected of AP. The prognosis for AP is not good, despite combinations of treatment. The disorder may run a chronic course. This may be because of our sunny climate and the sun-exposed occupations of patients.     

Cutaneous carcinoma and PUVA lentigines in Thai patients treated with oral PUVA

A total of 113 Thai patients who were treated with oral PUVA from 1979 to 1992 were examined for long-term cutaneous side effects of PUVA. Two psoriatic patients developed PUVA keratosis on non-sun-exposed areas. Both were skin type IV and had had phototherapy with UVB and sunlight previously. The total doses of UVA were 909 J/cm² and 242 J/cm² respectively. One psoriatic patient developed Bowen's disease. He had had a cumulative dose of UVA 2207 J/cm². He also had a past history of arsenic intake and phototherapy with UVB and sunlight. PUVA lentigines were seen in 58 patients (51.4%). It was associated with older age at starting PUVA, higher cumulative UVA dose and greater number of PUVA treatment. This study suggests that previous exposure to other risk factors is important for inducing skin cancer in populations with skin phototype III, IV and V treated with oral PUVA.     

Efficacy of a far erythemogenic dose of narrow-band ultraviolet B phototherapy in chronic plaque-type psoriasis

The aim of the present study was to examine the effect of far erythemogenic dose of narrow-band ultraviolet B (NB-UVB; starting dose at 35% minimal erythematous dose [MED]) on clinical response by measuring the severity, extent of disease and the changes in quality of life. Fifty patients with chronic plaque-type psoriasis were enrolled. Therapy was held for 3 days a week. The severity of the disease was assessed based on the Psoriasis Area and Severity Index (PASI) score and Dermatology Life Quality Index (DLQI) scores. The percentage improvement of PASI at 30 sessions was 68.99%. The improvement in DLQI scores at 30 sessions was 79.67%. Pearson correlation coefficients showed that PASI scores were not correlated with DLQI scores at the beginning of treatment ( P  = 0.330, r  = 0.14), but after the 30th session of NB-UVB therapy improvements in quality of life were correlated ( P  < 0.05, r  = 0.399). Therefore, far erythemogenic dose of NB-UVB is considered to be effective treatment for plaque-type psoriasis in our patients. However, we cannot confirm that it is safer than higher MED starting dose in term of cumulative UV irradiation.     

Topical PUVA Therapy for Chronic Hand Eczema

Seventeen patients with persistent chronic hand eczema were treated with topical 0.1% 8-methoxypsoralen and UVA (PUVA) for 8 weeks. Significant improvement was achieved in 5 cases (29%), moderate improvement in 9 (53%), and little improvement in 3 (18%). The mean number of PUVA treatments was 22.2, and the mean total UVA dose was 63.5 J/cm². There was no association between clinical response and duration of hand eczema, positive patch test reaction, or atopic status. Since topical PUVA has no risk of systemic side effects, it should be considered as an alternative treatment for patients with chronic hand eczema who are resistant to other topical medications.     

Efficacy of ALA-PDT vs blue light in the treatment of acne

BACKGROUND: Photodynamic therapy (PDT) is based on the principle of using light excitation of a wavelength-specific endogenous or exogenous photosensitizer to destroy the target tissue, and has shown efficacy in the treatment of certain non-melanoma skin cancers. PDT using aminolevulinic acid (5-ALA) has attracted attention in the treatment of acne vulgaris. METHOD: Twenty patients with moderate to severe acne vulgaris on the face were treated with four sessions of topical ALA-PDT with blue light (415 nm) on the right side of the face compared with blue light alone on the left side of the face, each treatment being 1 week apart. Ten percent of topical ALA was applied to acne spots on the right side of the face with a 1-h incubation period and the entire face was treated with 48 J/cm(2) of 415 +/- 5 nm light from an articulated LED planar array. Evaluation was performed by counting acne lesions at baseline, 4, 8, 12 and 16 weeks after the beginning of the treatment. Biophysical measurements included sebum levels and the erythema, and melanin indices. RESULT: At the given assessment times 4, 8, 12 and 16 weeks after the beginning of the treatment, the mean percent reduction in inflamed lesions counts tended to be higher in the ALA-PDT areas; it was 32%, 50.9%, 65.9% and 71.1%, respectively, compared with the blue-light-alone treatment, which was 20.7%, 27%, 57.7% and 56.7%, respectively, but without any statistical significance (P=0.092). There was no demonstrable significant change in sebum excretion, erythema or the melanin index after treatment. The side effects were pain, stinging, peeling, erythema, pruritus, oozing and pustules. These side effects were stronger on the ALA-PDT-treated side. CONCLUSION: From this study, the trend for ALA-PDT with blue light to be superior to blue light alone was observed, but it did not reach statistical significance. ALA-PDT had more side effects.     

A case of actinic prurigo in Thailand

Actinic prurigo is a separate entity from the polymorphous light eruption that affects American Indians. It has been reported mainly from North and South America, with only few reported cases from Britain or Asia. We report a case of actinic prurigo in a Thai girl who showed cheilitis and pruritic papules on exposed areas for three years. We were able to induce populovesicular lesions by three consecutive irradiations with 100 J/cm2 UVA and 2 minimal erythematous dose of UVB. However, three weeks after irradiation, a prurigo papule developed at the UVB irradiated site.     

Functional analyses of the eyelid skin constituting the most soft and smooth area on the face: contribution of its remarkably large superficial corneocytes to effective water-holding capacity of the stratum corneum

BACKGROUND/PURPOSE: The eyelid constitutes a unique area on the face because of its soft, smooth and thin skin distinct from that of other facial portions. Its softness facilitates their easy compliance to blinking movement, which is indispensable to protect the wet surface of the eyeball. Moreover, the skin of the eyelid does not show any prominent follicular orifices or an oily appearance even in adults. Despite such uniqueness, its biophysical characteristics have remained unclear as compared with other facial skin. METHODS: We conducted non-invasive instrumental measurements on the skin of the upper eyelid of 22 healthy Japanese adults in comparison with those of the adjacent facial skin, i.e. the cheek and nose. Additionally, we examined 10 adult patients with atopic dermatitis (AD) whose facial skin remained clinically free from skin lesions for at least 2 months. RESULTS: The eyelid skin showed high transepidermal water loss like other facial skin. Its skin surface hydration state was as high as that of the adjacent skin, despite the fact that the eyelid skin revealed extremely low amounts of surface lipids unlike its neighboring skin regions. However, in contrast to small corneocytes found in other facial areas, the corneocytes of the eyelid skin displayed a significantly larger surface size, suggesting that slow turnover of its stratum corneum (SC) takes place to allow sufficient maturation of the corneocytes, enabling them to exert efficient water-binding capacity. Its pH tended to be higher than that of the adjacent skin. Its superficial blood flow was significantly higher than that of others, although skin color assessment showed lower color values for redness than those of the other facial skin sites. In clinically non-lesional skin of adult AD patients, we found increased blood circulation and a higher parameter for redness, suggesting the presence of invisible mild inflammation in the dermis even long after subsidence of visible inflammatory changes. CONCLUSION: Our present biophysical findings suggest that, although the eyelid skin is poor in surface lipids, its extraordinary large superficial corneocytes play an important role in maintaining sufficient hydration state of its skin surface to keep it soft and flexible, enabling its good compliance with the blinking movement.     

Comparative studies of treatments for pityriasis lichenoides

Thirty patients with pityriasis lichenoides were divided into three groups. The first group was treated twice daily with applications of topical 0.02–0.1% triamcinolone cream. The second group was given the same regimen but in combination with oral tetracycline, one to two grams daily in divided doses. The third group was treated with oral psoralen and ultraviolet A (PUVA). The average durations of treatment in the three groups were 6, 7 and 2 months, respectively. The results of the treatment in the first group included two patients with complete remission, two with partial response and four with no response. In the second group, there was one patient with complete remission, eleven with partial response, and two with no response. Significant therapeutic results were observed in the third group; there were five patients with complete remission, two with partial response, and one with no response. Skin lesions of patients in the third group cleared completely or were markedly reduced with an average of 26 treatments at an average UVA dose of 68.80 joules/cm². We therefore concluded that PUVA is more effective than the other modes of treatment for pityriasis lichenoides.