This article reviews the effect of age and sex on the induction and elicitation of allergic contact dermatitis (ACD). We found that the incidence of ACD in childhood is lower than in adults; this may be explained by less exposure to allergens, lack of immune response and limited patch test studies in this age group. In the elderly, there is an age-dependent decrease in the incidence of ACD, with decreased sensitization to new allergens and waning responses in previously sensitized subjects. There is extensive controversy about the effect of sex differences in ACD. The induction phases of ACD in both sexes are different due to differences in exposure to the allergens from occupations, habits and cultures. Differences in elicitation phases of ACD in both sexes are not confirmed. Women tend to have a higher incidence of ACD and higher immunologic response to exposure allergens than men. Thus we can only imprecisely define the effect of age and sex on the induction and elicitation of ACD. Further prospective studies should be done to answer these questions.

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Pustular psoriasis (PuP) is a rare variant of psoriasis, presenting with non-follicular pustules on top of inflamed skin. It is mainly classified into generalized PuP (GPP) and localized PuP, of which the latter includes palmoplantar pustulosis (PPP) and acrodermatitis continua of Hallopeau (ACH). 1 While PuP manifests in adulthood in most patients, in some patients, PuP manifests before 18 years of age and is known as juvenile-onset PuP (JPP).While most cohorts agreed in terms of female predominance in patients, the mean age of onset varied with each population and subtype, falling between the late twenties and late forties. In addition, diabetes mellitus and hypertension are also commonly found among PuP patients. 2

A case of cutaneous sporotrichosis is reported for the first time in Thailand. The infection occurred in a 33-year-old Thai female who has been in good health and had no history of previous trauma or contact with any animals. Histopathology revealed pseudoepitheliomatous hyperplasia of the epidermis and a combination of granulomatous and pyogenic reactions in the dermis and subcutaneous tissue. Typical asteroid bodies (Splendore-Hoeppli phenomenon) with central yeast cells were seen. Sporothrix schenckii was recovered from skin biopsy specimens. The patient responded well to the treatment with saturated solutions of potassium iodide within three months. No recurrence was seen after more than six months follow-up.

Calcipotriol, a vitamin D analogue utilized for psoriasis, has irritation as its most frequent reported adverse event. However, studies on its irritant properties in humans have produced conflicting data. This study evaluates the effect of calcipotriol on stratum corneum barrier function, hydration and cell turnover in healthy volunteers, compared with sodium lauryl sulphate (SLS) as a model irritant. Calcipotriol 0.005% ointment and 1% aqueous SLS solution were applied for 60 min once daily for 2 weeks (5 consecutive days weekly) on untreated and on dansyl-chloride-labelled skin. Irritant responses were documented by visual scoring and by measurement of the transepidermal water loss (TEWL) and stratum corneum hydration (electrical capacitance), until day 18. Stratum corneum turnover time (SCTT) was the time in days between staining (day 0) and the disappearance of dansyl fluorescence. SLS caused more erythema, scaling, and a significant TEWL increase for 18 days. In contrast, calcipotriol induced erythema, and slightly but significantly increased TEWL on day 11 only, as compared with the vehicle control (P < 0.05). SLS, but not calcipotriol, caused skin dryness from day 4 to day 18. The shortest SCTT was obtained at SLS-exposed sites (11.2 +/- 0.7 days: mean +/- SD). Calcipotriol significantly shortened SCTT (16.3 +/- 1.1 days) when compared with its vehicle. Compared with the skin irritation induced by SLS, under these test conditions, calcipotriol is a far weaker irritant on normal human skin. In addition, calcipotriol accelerates stratum corneum turnover to a significantly greater extent than its vehicle.