J.L. Burton

Meta-analysis of placebo-controlled studies of the efficacy of Epogam in the treatment of atopic eczema. Relationship between plasma essential fatty acid changes and clinical response

Gamma‐linolenic acid in the form of a particular variety of evening primrose oil (Epogam) has been reported of value in the treatment of atopic eczema. Nine controlled trials of evening primrose oil were performed in eight centres. Four of the trials were parallel and five cross‐over. Doctors and patients assessed the severity of eczema by scoring measures of inflammation, dryness, scaliness, pruritus and overall skin involvement. Individual symptom scores were combined to give a single global score at each assessment point. In the analysis of the parallel studies, both patient and doctor scores showed a highly significant improvement over baseline (P < 0.0001) due to Epogam: for both scores the effect of Epogam was significantly better than placebo. Similar results were obtained on analysis of the cross‐over trials, but in this case the difference between Epogam and placebo in the doctors’global score, although in favour of Epogam, failed to reach significance. The effects on itch were particularly striking. There was no placebo response to this symptom, whereas there was a substantial and highly significant response to Epogam (P < 0.0001). When the improvements, or otherwise, in clinical condition were related to changes in plasma levels of dihomogammalinolenic and arachidonic acids, it was found that there was a positive correlation between an improvement in clinical score and a rise in the fatty acid levels.

Prostaglandins and pruritus.

We have found that pretreatment of human skin with prostaglandin El significantly lowers the threshold of human skin to itching evoked by both histamine and papain. Prostaglandins may thus potentiate pruritus in inflammatory skin disease, presumably by a non‐specific effect on nerve‐endings.

Metal corrosion by chloride in sweat: THE PROBLEM OF‘RUSTERS’ IN INDUSTRY

Workers in the precision engineering industry who readily corrode metal are known as‘rusters’. We have described two patients with this condition, and review current ideas with regard to its cause, detection, prevention and treatment.

Skin surface lipid composition in rosacea.

Skin surface lipid composition was measured in thirty‐one patients with rosacea and their age‐matched controls. Patients with rosacea had normal lipid composition, and there was no correlation between the lipid composition and the severity of the disease. Tetracycline therapy produced no measurable change in lipid composition.

Hazards of steroid therapy in hepatic failure

Three patients with extensive skin disease and liver failure are described. Two were treated with large amounts of topical corticosteroids and one with a small oral dose of betamethasone. The former two patients developed Addisonian crises when they failed to apply the topical steroids and all three patients developed aseptic necrosis of bone. This report emphasizes that the hazards of steroid therapy may be increased in patients with hepatic failure.

Skin surface lipids in seborrhoeic dermatitis

The common type of actinic keratosis is yellow-brown in colour, possesses an adherent scale and is less than i cm in diameter, with little tendency to continuing centrifugal spread. We have recently seen ten lesions arising on the face which were large, fiat and pigmented and in six cases had led the clinician to diagnose Hutchinsons malignant lentigo. Histology showed all to be pigmented actinic keratoses. The patients presented with a history of recent enlargement of an asymptomatic pigmented lesion on the face. All the lesions were larger than orthodox keratoses, having diameters between 1-5 and 4-0 cm. The surface was variably pigmented and either completely smooth, slightly verrucose or scaly. The histology of the lesions did not differ significantly from the more usual type of actinic keratosis, though epidermal and melanophage pigmentation was prominent. The melanocytes appeared normal in site, number and morphology. In the two cases in which a nodule was present within the pigmented keratosis, this had progressed to become a pigmented squamous cell carcinoma. The spreading pigmented type of actinic keratosis should be considered in the differential diagnosis of pigmented lesions of the face. Clinically, it may be difficult to distinguish from a Hutchinsons malignant lentigo.

Complications of topical corticosteroid therapy in patients with liver disease

The SER was fovmd to be significantly increased both in patients with breast cancer and in those with benign tumours as compared with age-matched controls. The raised SER was still apparent when sebum output was measured 6-12 weeks post-operatively, though there was a significant fall in a sub-group of eight patients in the 40-49 age group with cancer. These results suggest that an increase in SER occurs both with benign and malignant breast tumours and this increase may fall post-operatively. The rise in SER is apparently not due to surgical stress because no increase in SER was found in patients in whom it was measured before surgery for conditions such as cholecystectomy varicose veins ligation. These findings suggest that a specific sebotrophic stimulus is associated with benign and malignant breast tumours. The nature of this stimulus is uncertain.

The pruritic effect of bile salts

Koilonychia is most commonly seen as a sign of iron deficiency anaemia. It also occurs as an isolated congenital anomaly, as a temporary normal phenomenon in young children and in association with Raynauds phenomenon (Samman, 1972). Two motor mechanics presented to the Skin Department with koilonychia of fingernails which they attributed to contact with motor oils. Neither patient showed clinical or laboratory evidence of any underlying disease process. In an attempt to confirm or refute this association, eight major motor vehicle service centres were visited; the nails of 174 employees were examined, ninety-four motor vehicle mechanics and eighty controls such as paint sprayers, panel beaters, etc. Koilonychia was observed in five motor mechanics but in none of the controls. In view of previous reports that koilonychia maybe due to deficiency of sulphur-containing amino acids, nail keratin amino acids analysis was carried out. No significant difference was found compared with normal controls. Occupational koilonychia is thus not uncommon in motor mechanics, possibly due to contact with motor oils. The results of amino acid analysis suggest a different pathogenesis to other types of koilonychia.

CYCLOPHOSPHAMIDE AND PEMPHIGUS

A Finnish male aged 83 years had coronary heart disease; otherwise he had been healthy. The family history did not reveal any skin diseases. For at least 15 years the patient had noticed soft, flat, yellowish nodules (from i to 10 mm in diameter) on his neck, around the axillae and in the antecubital areas (Fig. i). The nodules were associated with slight intermittent itching. The lesions did not urticate on friction. On the basis of the clinical picture pseudoxanthoma elasticum was suspected. However, no angioid streaks were seen in his retina. Routine laboratory tests (including serum cholesterol and triglycerides) showed normal values. X-rays of the skull showed one well demarcated radiolucent lesion (10 mm in diameter) on the occipital border of the right parietal bone. The lesion might have been a mastocytoma. X-rays of the bones of the extremities showed small radiolucent lesions which were probably due to osteoporosis. A skin biopsy from the left axilla showed a moderate, patchy round-cell infiltrate in the dermis. Toluidine blue staining showed a markedly increased number of mast cells in this infiltrate. The elastic fibres were normal. Lipid stains revealed no fat in the lesions. The clinical picture of this patient was very similar to that of the case published by Griffiths & Daneshbod, suggesting pseudoxanthoma elasticum. The correct diagnosis can easily be made by detecting increased numbers of mast cells in skin biopsies with normal elastic fibers.