From February 1989 to January 1990, the Swiss Contact Dermatitis Research Group conducted a 1-year study to examine the frequency of sensitization to a series of 13 common preservatives. A group of 2295 consecutive outpatients with suspected allergic contact dermatitis (age range 7-90 years, with a mean age of 42; 911 males, 1384 females) was tested. The %s of positive reactions to the preservatives studied are as follows, in descending order: formaldehyde 5.7%, benzalkonium chloride 5.5%, Kathon CG 5.5%, thimerosal 4.2%, chlorhexidine digluconate 2.0%, DMDM hydantoin 1.7%, paraben mix 1.7%, chloroacetamide 1.5%, Bronopol 1.2%, imidazolidinyl urea 1.0%, quaternium 15 1.0%, triclosan 0.8%, 2,4-dichlorobenzyl alcohol 0.4%. These relatively high values suggest a heavy exposure of the Swiss population to topical preservatives. Compared to previous studies, the sensitization rate to Kathon CG has stabilized in Switzerland over the last 2 years. Sensitization to formaldehyde portrayed impressive geographical variation, with sensitization rates up to 9% in western and only 3% in eastern Switzerland. The low sensitization rate to parabens argues for their inclusion in a medicament or preservative series, rather than in the standard series.

Study of 14 patients with prurigo nodularis revealed that clinically the lesions were multiple, verrucous, and discrete and were set in normal-appearing skin. Microscopically, the lesions showed a vascular acanthomatous mass. The dermal nerves showed a tendency toward hyperplasia in parallel with the epidermal and vascular changes, but no evidence of neuroma formation was seen. Electron microscopic examination showed disorganization of the normal pattern of the myelin sheaths and axons of the dermal papillary nerves. The presence of epidermal mast cells was noted in the biopsy specimens of prurigo nodules from eight of the 14 patients.

Emulsifiers are common constituents of most topical preparations. To study the sensitization rate in a population with frequent use of these agents, we selected 47 patients with chronic or recurrent (> 1 year) inflammatory skin disease (leg ulcers, contact dermatitis, atopic dermatitis, psoriasis) for patch testing with the following emulsifiers: Tween 40 (polyoxyethylene sorbitan monopalmitate). Tween 80 (polyoxyethylene sorbitan monooleate), Span 60 (sorbitan monostearate), Span 80 (sorbitan monooelate), Arlacel 83 (sorbitan sesquioleate), Atlas G 2162 (polyoxyethylene oxypropylene stearate), Atlas G 1441 (polyoxyethylene sorbitol lanolin derivative), triethanolamine, Lanette O (cetylstearyl alcohol), Lanette N. 12 patients had at least 1 positive reaction (25.5%) at 3 or 4 days. Among them, 10 had leg ulcers (43.4% of the leg ulcer group), and 2 had contact dermatitis (13.3% of the contact dermatitis group). No positive reaction was observed in the other patients. When the patients were tested with their own topical preparations or wound dressings, 6 of them, all with leg ulcers, had positive reactions. These results show a surprisingly high prevalence of sensitization to emulsifiers in patients with chronic leg ulcers, in contrast to patients with other inflammatory skin diseases.

A case of alcohol contact urticaria is described. The immediate reactions with most of the primary alcohols were positive. Passive transfer was achieved.

A patient already published as a case of Richner-Hanhart syndrome (RHS) (stabilized corneal lesions and hyperkeratotic lesions on the palms and soles) proved to be associated with tyrosinemia type II. 2 other cases (sister and brother) with only typical dermatologic features of RHS and tyrosinemia type II are described. The treatment with a low phenylalanine and tyrosine diet improves the cutaneous lesions in our 3 cases.