J. McFadden

Cross-reactivity between streptococcal M surface antigen and human skin

Summary Psoriasis can be triggered by haemolytic streptococcal infections. As M protein is a major pathogenic surface antigen in these streptococci, the cross‐reactivity between streptococcal M protein surface antigens and human epidermis was investigated. The conserved component common to the few M proteins investigated consists of an alpha‐helical ‘coiled‐coil’ configuration, similar to sub‐units of human keratin. The amino acid sequence of protein M6, one of the M proteins that has been fully sequenced, was compared with that of 4721 ubiquitous peptides, by computer‐assisted analysis using a protein‐sequence data bank. Of all human proteins in the data bank 50‐Da keratin type 1 showed the closest homology with protein M6. Further evaluation revealed that this homology mainly involved the heptapeptide repeat patterns, which form the alpha‐helical “coiled‐coil” structure, in both M6 and 50‐kDa keratin.

Long-term cyclosporin for psoriasis

Thirteen patients with severe persistent psoriasis, intolerant of, or unresponsive to, other current treatments have been treated with cyclosporin (Cys) for periods varying from 12–25 (mean 18) months. The dose ranged from 1–4 mg/kg/day (mean 2.8 mg). There was a 72% reduction in the mean PASI score at 4 weeks, and at the end of the study, an 81% reduction. Adjuvant therapy with topical steroids was used in 11 of the 13 patients after the first 3 months of Cys treatment to persistent patches on an intermittent basis with beneficial effect. Six patients developed mild to moderate hypertension, in three this was controlled by a reduction in the dose of Cys, and in the other three by hypotensive agents. The mean serum creatinine rose from 72 to 90μM/1 during the study. Hypertrichosis occurred in seven of the 13 patients. Low dosage Cys is an effective treatment for clearing psoriasis and maintaining improvement on a long‐term basis.

Sulphamethoxypyridazine for dermatitis herpetiformis, linear IgA disease and cicatricial pemphigoid

One‐hundred and sixty‐eight cases of dermatitis herpetiformis were reviewed to compare the clinical response to and incidence of side‐effects from dapsone and sulphamethoxypyridazine. Thirty‐seven received sulphamethoxypyridazine (0·25–1·5 g/day) as a single agent therapy at some stage during their care and 161 had dapsone only (50–450 mg/day). Thirty of these patients received both drugs, but at different times. Both were highly effective in controlling the skin disease in 97% of patients on dapsone and 89% on sulphamethoxypyridazine. While 36 (22%) of dapsone‐treated subjects had intolerable side effects warranting a change in therapy, this occurred in only five (13·5%) of those treated with sulphamethoxypyridazine. Sulphamethoxypyridazine was also effective as a single agent in three patients with linear IgA disease who had suffered adverse effects from dapsone, and in 10 out of 15 patients with oral and cutaneous lesions of cicatricial pemphigoid.

Intralesional cyclosporin in psoriasis: effects on T lymphocyte and dendritic cell subpopulations.

On each of 10 patients with untreated plaque psoriasis, two symmetrical plaques were injected with cyclosporin A or placebo on six occasions over 12 days, in a double‐blind manner. Biopsies taken from these lesions at 14 days were examined for differences in cellular composition using a double‐labelling immunofluorescent technique.

Autoimmunity in dermatitis herpetiformis: Effect of a gluten-free diet

Of 165 patients with dermatitis herpetiformis OH) assessed for autoimmune status, autoantibodies were present in 101 (61.2%) and autoimmune disease in 20 (12%) on prekntation; a further nine patients (5.5%) had developed autoimmune disease at follow up (mean 8.1 years). Autoimmune status did not correlate with severity of small-bowel enteropathy as assessed by microscopy or by intraepithelial lymphocyte count. There was also no correlation with age, sex, duration of rash before presentation or age at onset of rash. Of 162 patients followed up (mean 8.1 yrs), 156 were on definitive treatment. In all treatment groups there was an overall trend to development of autoimmune disease/autoantibodies in a minority of patients. Autoantibodies/ autoimmune disease developed in subjects initially autoantibody-negative in 5/26 (19%) on a strict gluten-free diet, 5/16 (31%) on drug therapy plus gluten avoidance and 2/19 (11%) on drug therapy alone. Treatment with a gluten-free diet did not result in resolution of autoi...

14) Homology between glutenin and human connective tissue proteins

Although allergic contact dermatitis has been reported from an increasingly large number of plants, most cases of dermatitis are due to a relatively small number of plant groups in the U.K. Primula obconica remains the commonest house plant. The Asteraceae (daisy family) are increasingly recognized as common causes of weed dermatitis, in particular Taraxacum officinale (dandelion). Not all individuals will be detected by screening with sesquiterpene lactone mix. Alstroemeria spp. are important allergens in florists and X Cupressus leylandii and Hedera spp. (ivy) in gardeners. Finger-tip dermatitis is commonly caused by bulbous genera such as Narcissus, Tulipa and Hyacinthus, and Allium in food handlers. This poster describes the important botanical features of these plant families.

(25) Long‐term follow‐up of low‐dose cyclosporin treatment for psoriasis

One hundred and three cases of dermatitis herpetiformis were reviewed to compare the clinical response to and incidence of side-effects of dapsone and sulphamethoxypyridazine. Thirty patients received sulphamethoxypyridazine (o-5-i-5 g/day) as a single agent therapy at some stage during their care. Eighty-five received dapsone (25-400 mg/day) as a single agent treatment. Twelve of these patients had received both agents, but at different times. Both drugs were highly effective in controlling the skin disease. Only four (13%) patients on sulphamethoxypyridazine and two (2%) on dapsone changed to different drug treatment because of ineffective therapy. However, whereas only two (6-5%) changed from sulphamethoxypyridazine because of intolerable side-effects, 16 (19%) of the dapsone treated group changed for this reason. The major side-effects are shown in Table i.