Janet McLelland

Guidelines for the management of vulvodynia

These guidelines for the management of vulvodynia have been prepared by the British Society for the Study of Vulval Diseases Guideline Group. They present evidence‐based guidance for treatment, with identification of the strength of evidence available at the time of preparation of the guidelines.

Contact dermatitis with negative patch tests: the additive effect of allergens in combination

We deduced on theoretical grounds that conventional patch testing would be inadequate for the detection of sensitivity to multiple allergens. Fourteen patients with positive patch tests to two unrelated allergens were studied and the response to those two allergens was measured when tested singly or in combination, using 10 different pair combinations from 15 common allergens. With serial dilutions in chloroform (14 patients) and paraffin (four patients), the response was related to the log‐dose of the allergen, and change in skin‐fold thickness corresponded well with clinical grading. Single allergens diluted below the threshold for a patch‐test response gave a response when given in combination, the threshold for a response to one allergen being lowered by the presence of another. On the linear part of the dose‐response curves the response to the mixture of allergens was additive, the combined response being the sum of the individual components. Approaching the plateau region the response to the combination was greater than to the individual allergens but less than the sum of the single responses. The same results were obtained with allergens in paraffin. We conclude that conventional single allergen patch testing by itself is inadequate for the diagnosis of contact dermatitis.

A flow cytometric study of Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH), or histiocytosis X, is now generally considered to be a non‐malignant condition. A flow cytometric (FCM) study of a single case has, however, been published which claimed to provide evidence to contradict this. The presence of DNA‐ploidy as detected using this technique is a feature of malignant and pre‐malignant disease. In this reported single case, DNA‐ploidy was present but the clinical features of this patient were atypical for LCH. We have performed a FCM study of the DNA of nine biopsies of LCH lesions from six patients with well‐established disease. In addition, in one of these, fresh tissue studies including the use of an anti‐CD1 monoclonal antibody to specifically label the LCH cells were performed. In all cases the DNA content of the cells was entirely normal. We therefore found no evidence that LCH is a neoplastic disorder.

Measurement of cutaneous inflammatory reactions using a scanning laser-Doppler velocimeter

The performance of a new scanning laser‐Doppler velocimeter (LDV), which can rapidly measure blood flux over a large area of skin without contact with the skin surface, was compared with that of a conventional laser‐Doppler instrument. The vascular response was measured to a range of doses of UVB and dilutions of contact allergens and sodium lauryl sulphate. The detection threshold of the scanning LDV was equal to, or lower than, that of the conventional instrument. For allergic contact hypersensitivity reactions (ACH), the coefficient of variation was significantly less using the scanning LDV.

A comparison of molecular and enzyme‐based assays for the detection of thiopurine methyltransferase mutations

S‐Methylation by thiopurine methyltransferase (TPMT) is an important route of metabolism for the thiopurine drugs. About one in 300 individuals are homozygous for a TPMT mutation associated with very low enzyme activity and severe myelosuppression if treated with standard doses of drug. To validate the use of molecular genetic techniques for the detection of TPMT deficiency, we have determined red blood cell TPMT activity in 240 adult blood donors and 55 normal children. Genotype was determined by restriction fragment length analysis of polymerase chain reaction products in a cohort of 79 of the blood donors and five cases of azathioprine‐induced myelosupression, and this confirmed a close relationship between genotype and phenotype. In 17 of the 24 cases in which mutations were found, DNA was also available from remission bone marrow. In one of these cases, DNA from the remission marrow sample indicated the presence of a non‐mutated allele that had not been seen in the blast DNA sample obtained at presentation. These results indicate that polymerase chain reaction‐based assays give reliable and robust results for the detection of TPMT deficiency, but that caution should be exercised in relying exclusively on DNA obtained from lymphoblasts in childhood leukaemia.

Real-life experience of managing vulval erosive lichen planus: a case-based review and U.K. multicentre case note audit

Summary Background  There is a lack of published evidence for treatment and outcome measures for vulval erosive lichen planus (ELPV).

The relationship between plasma psoralen concentration and psoralen-UVA erythema

The plasma 8‐methoxypsoralen (8‐MOP) concentration was measured in 60 patients commencing psoralen photochemotherapy (PUVA). At the time of blood sampling each patient was phototested using a series of 10 exposures to UVA. The resulting erythema was measured objectively 72 h after irradiation and dose‐response curves for psoralen‐UVA erythema were constructed. Although the dose of 8‐MOP was calculated according to body weight, patients receiving 30 mg of 8‐MOP had a significantly lower mean plasma concentration than those receiving higher doses. There was no significant correlation between plasma 8‐MOP concentration and minimal phototoxic dose, either estimated visually or calculated from the dose‐response curves. However the slope of the dose‐response curve showed significant correlation with plasma 8‐MOP concentration. The variation between patients in the rate of increase of the erythemal response, but not the variation in threshold sensitivity, can be explained by differences in plasma psoralen concentration.

Solitary giant vulval syringoma

to lung, liver and brain. Although the exact mechanism of metastasis still remains unknown, histologically similar cancers from different origins might express the same adhesion molecules which determine the destination of metastasis. The reported frequency of cutaneous metastases from internal cancers ranges from 0 ́6% to 9%. This variation may be largely due to a lack of uniformity in data gathering. Some studies are on terminal cases and others on living patients. Some reports include melanomas, sarcomas, leukaemias and lymphomas and others exclude some or all of them. Spencer and Helm analysed the most reliable autopsy data from 7518 patients with internal cancer and found four cases of cutaneous metastasis from cancers of the eyes. It was unclear whether those four cases included cancers originating from the lacrimal gland.

Comparison of peanut agglutinin and S100 stains in the paraffin tissue diagnosis of Langerhans cell histiocytosis

We compared peanut agglutinin and S100 stains on paraffin embedded material from a variety of sites involved in Langerhans cell histiocytosis (LCH), The two techniques were comparable in terms of ease of performance, time taken and cost. Peanut agglutinin produced dense cell surface and paranuclear staining of the characteristic LCH cells seen in lesions, which was easier to distinguish than the more diffuse cytoplasmic staining produced by the S100 technique. This characteristic staining pattern is more specific than that for the S100 protein which is present in a variety of different cells, including some malignant histiocytes. We recommend that peanut agglutinin be used as a routine diagnostic test for all samples suspected of being LCH.

(11) Langerhans cell histiocytosis: is this a malignant process?

cellotape and then carbon coated. They are scanned at a tilt of 45° and analysed at 20 kn for 100 s (live time) using an Hitchi H-3010 electron microscope fitted with an energy dispersive detector coupled to a Link Systems Ltd. 860 Series i Multichannel analyser. Spectra are collected at the root, above the root, 05 cm above the root, midshaft and tip ofthe hairs, and processed using a Link Systems Ltd. ZAF/PB programme. The elements considered are sulphur, calcium, chlorine, potassium, sodium, phosphorus, silica, zinc, iron and copper. The results are expressed as percentages of the total spectrum minus the background. Spectra recorded from normal hairs show that the major element detected is sulphur which is constant along the hair shaft. There is a linear increase in calcium levels from root to tip. The roots of anagen hairs contain more sulphur and potassium than telogen roots. We have described a potentially useful method of assessing the elemental composition of hair.