International Integrative Photodermatology in Southeast Asia.

Within the broader field of dermatology, the practice of photodermatology is quite important. Many patients suffer from incurable, chronic, long-lasting, and psychologically traumatizing skin conditions, such as severe psoriasis, devastating vitiligo, intolerable atopic dermatitis, and refractory mycosis fungoides, for which standard medical treatments have produced limited results. Advanced targeted medicines, including the new biologics, offer higher efficacy rates, but the treatment costs are so exorbitant that most patients simply cannot afford to pay them. Photomedicine, however, may still provide hope for many patients with difficult and refractory skin diseases. In contrast to the advanced medicines, this type of treatment is much more affordable. Phototherapy also has fewer unacceptable side effects compared with immunosuppressive drugs and the newer targeted medicines. Phototherapy can also be performed on children, pregnant women, and even cancer patients, whereas the new biologics cannot be used in these patients.

Influence of vitamin C on the elicitation of allergic contact dermatitis to p-phenylenediamine.

BACKGROUND: Hair dyes represent one of the most important causes of allergic contact dermatitis resulting from the use of cosmetic products. The principal causative chemistry is associated with oxidation products of p-phenylenediamine (PPD) and closely related substances. OBJECTIVES: To examine whether prior application of the antioxidant vitamin C to the skin was able to reduce the cutaneous allergic response to PPD. METHODS: Twenty eight volunteers with a proven history of contact allergy to PPD were recruited. Each was tested with a range of PPD doses and PPD-containing hair dye on untreated skin and skin pretreated for 10 min with a vitamin C formulation. RESULTS: Pretreatment of skin sites with vitamin C led to a reduction in the intensity, or even ablation, of the cutaneous allergic reaction to PPD in ∼75% of cases as compared with untreated skin. CONCLUSIONS: The results suggest that treatment of the skin adjacent to the hair-bearing area with antioxidant could form part of a strategy to reduce the burden of cosmetic allergic contact dermatitis caused by hair dyeing.

Genetic evidence for involvement of the IL23 pathway in Thai psoriatics.

A recent genome-wide association analysis of psoriasis identified IL12B and IL23R as significantly associated with psoriasis. Here we report association test results of a Thai cohort consisting of 206 psoriasis cases and 114 controls. The IL23R SNPs rs7530511 and rs11209026, and IL12B SNPs rs3212227 and rs6887695 were genotyped using Taqman assays. Data were analyzed using a logistic regression model for linear trend of association. One of the IL23R markers, rs7530511, was marginally significant (P = 0.017). The other IL23R marker, rs11209026, was not polymorphic. One of the IL12B markers, rs3212227, showed significant association with psoriasis (OR = 1.64, P = 0.0058) while the other, rs6887695, did not (OR = 1.29, P = 0.12). Haplotype analysis of the two IL12B SNPs yielded highly significant association (P = 0.00081, OR = 1.73). These results showed that IL12B is an important genetic factor in psoriasis pathogenesis in the Thai population, with an association strong enough to yield significant confirmatory evidence using a modest sample size. Together with previously reported evidence for IL12B association in Caucasian, Japanese, and Chinese psoriatics, our results support the hypothesis that genes encoding components of the IL23-mediated inflammatory pathway are important determinants of psoriasis pathogenesis across multiple racial groups.

A study on the knowledge, attitudes and practices of Southeast Asian dermatologists in the management of atopic dermatitis.

INTRODUCTION: This study evaluated the knowledge, attitudes and practices of Southeast Asian dermatologists in the management of atopic dermatitis (AD). MATERIALS AND METHODS: A questionnaire survey of 255 dermatologists in Indonesia, Malaysia, the Philippines, Singapore, Thailand and Vietnam. RESULTS: Familiarity with diagnostic criteria varied considerably. The usage of moisturisers by the respondents from Vietnam and Indonesia was significantly less frequent than the other countries. Most respondents (91% to 100%) used topical corticosteroids in children with mild-to-moderately severe dermatitis. Some respondents in the Philippines (17% to 19%) and Vietnam (11% to 25%) only used topical corticosteroids for severe disease. For infected eczema, most respondents would prescribe systemic antibiotics for mild-to-moderate infection. A minority in the Philippines (14%) and Vietnam (11%) did so only for severe infection. The top 4 systemic antibiotics prescribed most frequently were: erythromycin, cloxacillin, cephalosporin and amoxicillin/clavulanic acid. In Indonesia, a large proportion of the respondents (47%) prescribed amoxicillin most frequently. The majority of respondents (60% to 100%) prescribed both sedating and non-sedating oral antihistamines. Most respondents used oral corticosteroids to treat severe AD. Some in Malaysia, Singapore and Vietnam used cyclosporin (7% to 58%), azathioprine (5% to 31%) and methotrexate (5% to 14%). With the exception of those in Singapore, the majority of respondents (71% to 97%) did not use phototherapy. CONCLUSION: Familiarity with diagnostic criteria, the early and judicious use of moisturisers and topical corticosteroids, as well as the treatment of Staphylococcus aureus superinfection with penicillinase-stable antibiotics should be emphasised in this region.

Elicitation response characteristics to permanent hair dye in paraphenylenediamine-allergic volunteers.

BACKGROUND: Elicitation response characteristics to complete permanent hair dye products in paraphenylenediamine (PPD)-allergic volunteers have not previously been explored in detail. OBJECTIVES: To assess the elicitation response characteristics observed in PPD-allergic volunteers upon patch testing with complete hair dyes. METHODS: PPD-allergic volunteers were assigned to 1 of 3 groups depending upon whether they elicited + (group 1), ++ (group 2) or +++ (group 3) reactions following the standard diagnostic procedure. Each group was subsequently patch tested with 2 complete hair dyes (A and B) for 30 min, 1 hr and 24 hr. Patch sites were examined 1 day, 2 days and 3 days after patch removal. RESULTS: Exposure to either hair dye for 30 min or 1 hr was insufficient to yield positive patch test reactions in all of the PPD-allergic patients in groups 1 or 2. Application of either hair dye for 24 hr was sufficient to yield positive reactions in all of the individuals within groups 2 and 3. CONCLUSIONS: The frequency of positive patch test reactions observed following 24-hr exposure to complete permanent hair dyes is comparable to that observed following 48-hr exposure to 1% PPD/petrolatum in those individuals whose degree of sensitization is such that they typically present ++ or +++ reactions diagnostically.

The impact of exposure variables on the induction of skin sensitization.

Whereas many investigations of the variables associated with the elicitation of allergic contact dermatitis have been undertaken, to the point where we can begin to predict the likelihood of elicitation occurring in a given situation, the same is not true for the induction of skin sensitization. Studies have demonstrated that increasing dose has an impact; in an experimental setting, a number of variables received attention some decades ago. However, in the work reported here, the relative importance of the frequency and the duration of exposure is highlighted. In an investigation using a human repeated insult patch test, it was demonstrated that reduction of the exposure duration from 48 hr to 5 min decreased the rate of sensitization to 1% p-phenylenediamine (PPD) from 54% to 3%. However, in an extended clinical study, it was observed that infrequent but longer duration and higher concentration exposure to PPD was significantly less likely to induce sensitization compared to more frequent, short duration, and lower concentration exposure. Detailed statistical analysis of the results indicated that the most important factor driving the induction of skin sensitization was the number of exposures.

Disseminated Mycobacterium chelonae cutaneous infection: recalcitrant to combined antibiotic therapy.

A 25-year-old Thai housewife had a history of tuberculosis of the lymph nodes for six years that had been successfully treated with a course of anti-TB drugs. She developed several red, circumscribed, infiltrative plaques composed of umbilicated papules and pustules on her face and upper part of the body with cervical lymphadenopathy six months later. A pus smear from the lesion grew acid fast bacilli (AFB). Histopathological examination showed a mixed cell granuloma suggestive of infection. A T cell study showed a low CD4 count, and multi skin tests indicated cutaneous anergy. Culture from a biopsy specimen taken from the skin lesion grew M.chelonae; the cultures from blood, urine, and bone marrow. The lesions were not responsive to an anti TB drug given for 2 months based upon the results of the AFB positive pus smear before the culture and sensitivity reports were obtained. Since then the patient was treated with antibiotics according to the results of the sensitivity tests. A combination of amikacin and clarithromycin was started and hyperthermic therapy was later added with a partial response. Based upon the sensitivity test, kanamycin was introduced but had to be stopped because of ototoxicity. Sparfloxacin was used with an effective result but was discontinued for economic reasons. Finally, clarithromycin in combination with clofazimine and cryotherapy were given for a year before the lesions healed completely. It took a three years duration for the total course of treatment for this patient. She is still in remission after two years of follow-up period. This extensive cutaneous M.chelonae infection needed a prolonged combination of antibiotics with the addition of cryotherapy for the non-responsive lesions.

Papillon-Lefevre syndrome: a case report.

We report the first diagnosed case of Papillon-Lefevre syndrome in Thailand. The patient is the youngest child of consanguinous parents, and she has had symmetrical hyperkeratotic plaques on both plantar surfaces since birth with a history of chronic gingivitis, periodontitis, and premature loss of primary dentition. The histologic study revealed compact hyperkeratosis with epidermal acanthosis. Radiologic studies of the skull were normal. The radiographic panoramic view of the oral cavity revealed generalized severe vertical and horizontal alveolar bone loss. The immunologic analysis of polymorphonuclear leukocyte phagocytic function by nitrobluetetrazolium test (NBT test) showed decreasing response to latex stimulation. Serum parathyroid hormone, calcium, phosphate, and alkaline phosphatase levels were within normal limits. The skin lesions were temporary relieved with topical keratolytic agents. The oral lesions were improved by the extraction of hopeless teeth and conventional periodontal treatments.