Editor's choice
Authors: None Gawkrodger
Journal: British Journal of Dermatology (1999)

H-M.Sheu, S-C.Chao, T-W.Wong, J Y-Y.Lee, J-C.Tsai Human skin surface lipid film: an ultrastructural study and interaction with corneocytes and intercellular lipid lamellae of the stratum corneum (p. 385) Sebum is secreted by sebaceous glands and is a complex mixture of lipids which forms a fluid film over the skin surface. After secretion, sebum mixes with lipids from keratinocytes and forms a skin surface lipid film (SSLF). Dr Sheu and colleagues from Taiwan have studied the SSLF and its interaction with the upper layers of the stratum corneum using fluorescent and electron microscopic techniques. The authors find that SSLF forms an amorphous sheet of variable thickness on the skin surface and does not consist of lipid droplets as had been assumed. The SSLF is itself composed of numerous fine granules and may contain lipid derived from corneocytes. The figure shows a frozen section of facial skin stained with oil red O illustrating linear staining in the intercellular membrane regions of the stratum corneum (black arrows) with irregular foci of lipid particles in the outer stratum corneum (asterisks). D.Tsuruta, K.Kaneda, H.Teramae, M.Ishii In vivo activation of Langerhans cells and dendritic epidermal T cells in the elicitation phase of murine contact hypersensitivity (p. 392) The mechanisms of the elicitation phase of contact sensitivity are now quite well defined. Using a mouse model, which may show some differences from the human, Dr Tsuruta and colleagues investigate the kinetics involved in activation of Langerhans cells and dendritic epidermal T cells in the elicitation of contact allergy. They describe a biphasic activation with increases at one hour and 24 hours after the application of hapten to the epidermis. The early phase of this activation was independent of interferon-γ, tumour necrosis factor-α and interleukin 1-β, although the latter phase was mediated through the effects of these cytokines. In the early phase there was Langerhans cell-to-dendritic epidermal T cell apposition. These experiments suggest that the early and late phases of the reaction have different mechanisms. The figure shows the appearance of green staining Langerhans cells and red staining dendritic T cells at 24 hours, when there is less apposition than at one hour. O.Jumbou, J.M.N'Guyen, M.H.Tessier, B.Legoux, B.Dréno Long-term follow-up of 51 patients with mycosis fungoides and Sézary syndrome treated with interferon-alfa (p. 427) Interferon-alfa is now recognised as an effective treatment for mycosis fungoides and Sézary syndrome. Response rates are between 29 and 80% with a 4–35% rate of complete remission. Dr Jumbou and colleagues describe their experiences in 51 patients with cutaneous T-cell lymphoma treated by subcutaneous interferon-alfa and followed for a mean of 43 months. The mean length of treatment was 16 months. The authors noted a complete remission in 21 patients, with partial remission in 13 and stable disease in 17. Out of the 21 patients who experienced a complete remission (the mean time for which was four months), 12 relapsed within a mean period of 7.5 months. Ten patients who did not relapse were observed over a period of 31 months. The figure shows the probability of survival in percentage terms. H.J.van der Rhee, L.M.T.van der Spek-Keijser, R.van Westering, J.W.W.Coebergh Increase in and stabilisation of incidence and mortality of primary cutaneous malignant melanoma in western Netherlands, 1980–95 (p. 462) The incidence of malignant melanoma continues to rise in many western countries. During the 1980s, the authors from the Netherlands noted an increase in the incidence of more than 50% for women and more than 100% for men. Since 1989, the rate has remained stable for men but has increased slightly for women. Despite this increase in incidence, the mortality rates have remained largely unchanged for both men and women. The authors noted a decrease in the median Breslow thickness of the malignant melanomas over the period of their study, with a decline in the female to male ratio from 2.0 to 1.5. Most interestingly, they observed an increase between 1980 and 1995 in the numbers of malignant melanomas with a Breslow thickness of less than 1.5 mm (see figure showing incidence for women: in situ is shown by ○; less than 1.5 mm +; 1.51–3.5 mm *; more than 3.5 mm ▪). Given the recent stabilisation of rates overall and the trend towards thinner tumours, screening and surveillance should be concentrated on high risk groups who may be predisposed to thicker lesions. T.Kawakami, R.Saito Acquired reactive perforating collagenosis associated with diabetes mellitus: eight cases that meet Faver's criteria (p. 521) Reactive perforating collagenosis may occur as an inherited or autosomal recessive condition or as a sporadic disorder. The sporadic form is associated with systemic conditions, particularly diabetes mellitus, and it can be precipitated by renal dialysis. Histologically, there is transepidermal elimination of necrotic basophilic collagen bundles (see figure). Clinically, the lesions are umbilicated papules or nodules with an adherent keratotic plug. In the eight patients described, who had acquired reactive perforating collagenosis associated with diabetes, the lesions resolved within four to eight weeks. The authors consider that the perforating collagenosis may represent a cutaneous response to superficial trauma, perhaps predisposed to by diabetic vasculopathy. H.Nishie, S.Imayama, M.Furue Non-typhoid Salmonella infection associated with ‘rose spots’ (p. 559) It is not uncommon for a dermatologist to be called to a general medical ward, only to diagnose a non-specific eruption which may represent a viral infection or perhaps a drug eruption. The physical attributes of rose spots could easily be dismissed as being non-specific in nature. The authors describe their occurrence in association with a non-typhoid salmonella infection. The eruption (see figure) cleared within three days of treatment with chloramphenicol. A.Akagi, N.Tanaka, Y.Ohnishi, A.Fujioka, A.Kawada, S.Tajima, A.Ishibashi Discoid lupus erythematous in a seborrhoeic facial distribution (p. 561) Facial dermatoses often prove to be a diagnostic problem for clinical dermatologists and it is sometimes difficult to make an exact diagnosis at the first consultation. Seborrhoeic dermatitis, for example, can be easily confused with a number of other conditions. Dr Akagi and colleagues from Japan describe two women who were diagnosed as having discoid lupus erythematosus, in whom the facial eruption occurred in a ‘seborrhoeic’ distribution (see figure). One patient had a plaque of discoid lupus erythematosus on the scalp, but the other patient did not have any additional lesions outside of the periocular region and nostril rim. The histology suggested lupus erythematosus in both cases. U.Wollina The response of erythematous rosacea to ondansetron (p. 562) Despite being so common, the cause of rosacea is still unknown. Flushing is often an early sign, but is not seen in every case. Nonetheless, there are suggestions that neuropeptides may be involved, at least in the early stages. Ondansetron is a serotonin antagonist and is used to prevent or treat nausea, vomiting and flushing associated with chemotherapy. It is also reported to inhibit certain neurovascular reflexes. In this paper, Dr Wollina describes the use of ondansetron in two patients with telangiectatic and erythematous rosacea (Figure). Both improved with this treatment. Although anecdotal, the observation should encourage further research into the vascular changes in rosacea.