A predictive model of the requisite minimal erythema dose between 308-nm monochromatic excimer light and 311-nm narrowband Ultraviolet-B light.

BACKGROUND: There are limited data in the relationship between the minimal erythema dose (MED) of 308-nm monochromatic excimer light (MEL) and 311-nm Narrowband UVB (NB-UVB). OBJECTIVE: To establish a predictive model of the relationship between MEDs of both wavelengths. METHODS: An MED test was performed on the back of 40 healthy Thai volunteers. One side was irradiated with 308-nm MEL, and the opposite side was irradiated with 311-nm NB-UVB. The correlation and a predictive model of the relationships were then analyzed. RESULTS: There was a positive correlation in the MED of both wavelengths (r = 0.82, p < 0.001). A predicted MED of 308-nm MEL was based on Y = 62.421 + 0.439X, where Y and X were a predicted MED of 308-nm MEL and an actual 311-nm NB-UVB, respectively. This model could predict an MED of 308-nm MEL by using an actual MED of 311-nm NB-UVB with a root mean square difference of 13.64%, and a mean bias difference of 0.63%. LIMITATION: All volunteers were Fitzpatrick's skin phototype type IV. The predictive model might not generalize to other skin phototypes. CONCLUSION: We established a predictive model of the relationship between MED of 308-nm MEL and 311-nm NB-UVB with acceptable accuracy.

Fragrance allergy could be missed without patch testing with 26 individual fragrance allergens.

BACKGROUND: In 2003, the EU Cosmetics Directive stated that 26 fragrance substances must be listed on the cosmetic product ingredient labels. Not all of these 26 fragrance substances are detected by the usual screening markers comprising fragrance mix I, fragrance mix II, and Myroxylon pereirae. OBJECTIVES: To evaluate the usefulness of testing with the 26 individual fragrance substances in addition to the standard fragrance screening markers. MATERIALS AND METHODS: Three hundred and twelve consecutive patients were patch tested with our baseline series and the 26 specific fragrance substances required to be declared on cosmetic product ingredient labels in accordance with the EU Cosmetics Directive. RESULTS: Positive reactions to at least either one of the 26 individual fragrance substances or the usual fragrance screening markers were seen in 84 of 312 patients (26.9%). Fifteen of these 84 patients (17.8%) reacted negatively to the fragrance screening markers. The most common individual fragrance allergens were cinnamyl alcohol (11.2%), cinnamal (9%), and hydroxycitronellal (3.8%). Sixty-two of 312 patients (19.8%) had at least one positive reaction to the fragrance screening markers. CONCLUSION: Additional patch testing with the 26 individual fragrance allergens, or with the commonest fragrance allergens identified within these 26, should be performed to optimize the detection of fragrance allergy. Cinnamyl alcohol and cinnamal are important fragrance allergens in Thailand.

Persistent post-occupational dermatitis.

Wall and Gebauer (Contact Dermatitis 1991: 24: 241-243) first described persistent post-occupational dermatitis (PPOD) as ongoing dermatitis for which there is no obvious present cause, precipitated by prior occupational contact dermatitis (OCD). We propose that individuals exhibiting PPOD lose the capacity for resolution of their condition upon removal from exposure to causative agents and subsequently develop persistent dermatitis, which can be continual or intermittent. Accordingly, we suggest modification of criterion 6 of the OCD criteria developed by Mathias (J Am Acad Dermatol 1989: 20: 842-848): 'Removal from exposure initially leads to improvement of dermatitis, however, over time there may be incomplete or no improvement, despite removal from exposures at work'. To satisfy the definition of PPOD, individuals must meet at least 4 of the 7 criteria, including the altered criterion 6. We present 6 cases of PPOD exemplifying these scenarios, which met the altered Mathias criteria. In some cases, subsequent failure to recognize the initial work relatedness of their skin conditions resulted in the termination of workers' compensation benefits. This situation is particularly relevant in the Australian context. The diagnosis of PPOD needs to be considered in all individuals with work-initiated dermatitis who present with ongoing endogenous-like eczema.

Topical corticosteroid allergy in an urban Australian centre.

The reported prevalence of allergic contact dermatitis from topical corticosteroids in clinical populations, in the period 1993-2002, varied from 0.55 to 5.98%. This study is a retrospective analysis of 1153 individuals undergoing routine patch testing in an Occupational Dermatology Clinic in Melbourne, Australia. We report a rate of 0.52% for positive patch test reactions to 5 corticosteroids. Corticosteroids tested were betamethasone-17-valerate, budesonide, Diprosone cream (betamethasone diproprionate 0.05%) (Essex-Pharma, a division of Schering-Plough Pty Ltd, Sydney, Australia), tixocortol-21-pivalate and triamcinolone acetonide. Population characteristics were described using the MOAHL (M = percentage of males tested; O = occupational; A = atopics; H = patients with hand eczema; L = patients with leg ulcers or stasis eczema) index. Prescribing patterns, rate of referral and rate of relevant positive patch test reactions were characterized for the region. These results were compared to the rates of corticosteroid allergy and patch testing methodologies from published international studies. It was noted that many high-sensitization potential corticosteroids were not available in our region. Although a low percentage of leg ulcers and stasis dermatitis may be associated with a lower rate of corticosteroid allergy, this association may be confounded by regional factors such as prescribing habits and the local availability of corticosteroids. We conclude that the low rate of topical corticosteroid contact allergy reported by our clinic is associated with regional availability and prescribing practices and the scarcity of stasis dermatitis and leg ulcers in our clinic population.

Immediate-type latex hypersensitivity in a hairdresser.

Hairdressers commonly develop contact dermatitis caused by either skin irritants or allergens to which they are exposed. Those using latex gloves are also at risk of developing immediate hypersensitivity reactions to latex. We present a hairdresser with hand dermatitis, primarily as a result of immediate-type hypersensitivity to latex causing contact urticaria, diagnosed with radioallergosorbent testing. Only three previous studies have reported latex allergy in hairdressers. This condition needs to be considered as a differential diagnosis in hairdressers presenting with hand dermatitis and a history of wearing either rubber or disposable latex gloves.