S. K. Ng

Sweet's syndrome: a spectrum of unusual clinical presentations and associations.

Background  Sweets syndrome (SS) is the prototypic neutrophilic dermatosis. First described in 1964, the characterization of new clinical associations, unique histopathological findings and clinical variants have stimulated much interest and discussion recently. However, the prevalence of these unusual variants and clinical associations within a single cohort of patients, has not been described.

Changing trends in the epidemiology of contact dermatitis in Singapore

All patients seen in the Contact Dermatitis Clinic of the National Skin Centre, Singapore (and the former Middle Road Hospital) between January 1986 and December 1990 were analysed retrospectively. 5557 patients comprising 2934 (47.4%) males and 2923 (52.6%) females were patch tested, 3154 (56.8%) patients had 1 or more positive reactions. The majority of the patients wore Chinese (78.0%), followed by Malays (11.5%), Indians (8.1%) and other minority races (2.4%). The majority of positive reactions belonged to the 21.40 age group. The incidence of Positivity decreased after 61) years. The commonest allergens responsible were nickel (17.7%), fragrance (13.3%); neomycin (6.9%), colophony (6.6%)and proflavine (6.5%). Both neomycin mid proflavine were commonly used as over‐the‐counter medicaments. Compared loan earlier report in 1988, there were differences in the incidence of contact sensitivity to some allergens. Potassium dichromate. which used to be a common allergen, was less common. Some allergens (carba‐mix, naphthyl‐mix, caine‐mix and PCMX) have been removed from our standard series as they were uncommon causes of contact allergy. Thimerosal and Amerchol L‐101 were added in their place.

Allergic contact dermatitis from nickel in eyeshadow

From the histories and patch test results, we conclude that the dermatitis was caused by delayed hypersensitivity to 1,2D in all cases described. The positivity to methyl acrylate, found in only 1 worker, was not due to current contact with this substance and was not responsible for the dermatitis. In the literature, we have found only 2 cases of allergic contact dermatitis from 1,2D, with patch tests positive at 1% pet. (2). Other references (3, 4) concern workers exposed to DD, a soil fumigant containing 1,2D and 1,3-dichloropropene, but here, the sole sensitizer has been considered to be 1,3dichloropropene. The rarity of this kind of investigation may be due to the general belief that dermatitis from solvents (especially chlorinated ones) is always irritant in nature. The allergic risk of 2,4 D is probably underestimated in industry. Furthermore, the presence of SHORT COMMUNICATIONS

Positive patch-test reactions to para-phenylenediamine, their clinical relevance and the concept of clinical tolerance.

406 patients were patch tested over an 18‐month period (January 1998 to June 1999) at a dermatology referral centre. 33 patients (8.1%) had a positive reaction to para‐phenylenediamine (PPD). 20 patients were experiencing PPD hair dye dermatitis (present relevance, 61%), 2 were using PPD hair dyes without developing dermatitis (clinical tolerance, 6%), 4 had previously used PPD hair dyes with dermatitis in the past (past relevance, 12%), 3 had previously used PPD hair dyes without dermatitis (past exposure, 9%) and 4 had no known exposure to PPD (unknown relevance, 12%). Of the 20 patients whose test results were of present relevance, 17 avoided PPD hair dyes, resulting in total clearance of the dermatitis in all except 3, who had concurrent endogenous eczema. 3 continued using PPD hair dyes: 2 had recurrent contact dermatitis and 1 avoided dermatitis with meticulous technique. The 2 patients with clinical tolerance continued using PPD hair dyes with no dermatitis.

Treatment of toxic epidermal necrolysis in AIDS with intravenous immunoglobulins

Summary Individuals with AIDS are at higher risk of developing severe cutaneous adverse drug reactions. We report two AIDS patients with drug‐induced toxic epidermal necrolysis (TEN). The suspected drugs were discontinued. Both patients were treated with intravenous human immunoglobulins at a dose of 1 g/kg body weight per day for two consecutive days and both experienced a good outcome. Intravenous immunoglobulin potentially lowers the morbidity and mortality of TEN and shortens the duration of the patients hospitalization.

Atopy patch testing with aeroallergens in patients with atopic dermatitis and controls in Singapore

The role of allergy in atopic dermatitis is controversial. The atopy patch test (APT) has been used to investigate the association between atopic dermatitis and aeroallergen allergy. To determine the proportion of patients with atopic dermatitis with positive patch tests to common local aeroallergens and to compare this to controls with and without respiratory atopy, we performed APT, skin‐prick tests (SPT) and IgE radioallergosorbent tests (RAST) on 73 patients with atopic dermatitis and on 38 nonatopic controls (13 with and 25 without respiratory atopy). The allergens used were house dust mite, cat dander, Bermuda grass and German cockroach. Only the APT for house dust mite showed a significant difference between the two groups. APT for house dust mite correlated with the RAST test, while APT for cat fur correlated with the SPT. The APT may be useful to evaluate aeroallergens in atopic dermatitis, but further work is needed to make it more reliable.

Two Singaporean cases of guttate leucoderma in Darier's disease.

1 Laugier P, Hunziker N. Pigmentation melaniques lenticulare, essentielle, de la musqueuse jugale et des levres. Arch Bel 1971; 26: 391–9. 2 Mignogna MD, Muzio LL, Ruoppo E et al. Oral manifestations of idiopathic lenticular mucocutaneous pigmentation (Laugier–Hunziker syndrome): a clinical histopathological and ultrastructural review of 12 cases. Oral Dis 1999; 5: 80–6. 3 Lampe AK, Hampton PJ, Woodford-Richens K et al. Laugier–Hunziker syndrome: an important differential diagnosis for Peutz–Jeghers syndrome. J Med Genet 2003: 40: e77. 4 Velero A, Shert K. Pigmented nails in the Peutz–Jeghers syndrome. Am J Gastroenterol 1961; 42: 56–8. 5 Hanada K, Baba T, Sasaki C et al. Successful treatment of mucosal melanosis of the lip with normal pulsed ruby laser. J Dermatol 1996; 23: 263–6.

Comparison between 1-day and 2-day occlusion times in patch testing

The results of patch tests carried out with disperse dyes at reduced concentrations are shown in Table 1. Patch tests with disperse mix gave positive reactions in all subjects sensitized to l or more disperse dyes (31/ 31). In control subjects, no irritant or late reactions were observed. TLC carried out on batches of disperse mix 4, 10 and 14 months after preparation, freshly prepared disperse mix and single components, demonstrated stability (Fig. I).

Prurigo pigmentosa: a report of two cases that responded to minocycline

Prurigo pigmentosa (PP) is an unusual pruriginous dermatosis of unknown aetiology and is often misdiagnosed. We report two people (a 16‐year‐old Chinese boy and a 21‐year‐old Chinese woman), who presented with clinicopathological features consistent with PP. Both patients were successfully treated with minocycline. Better knowledge of this disease will lead to early recognition and appropriate treatment.

Contact dermatitis: a common adverse reaction to topical traditional Chinese medicine.

Background  Over the past decade, there has been an increase in the use of topical traditional Chinese medicine (TTCM). The most common adverse event seen in the use of TTCM is contact dermatitis. This retrospective study was designed to determine the types of commonly used TTCM in Singapore causing contact dermatitis.