Pauline M. Dowd

Increased vanilloid receptor VR1 innervation in vulvodynia

Vulvodynia is characterised by painful burning sensation, allodynia and hyperalgesia in the region of the vulval vestibulus. While in many patients the cause of vulvodynia remains uncertain, we and others have previously shown increased intraepithelial and papillary innervation in vulvodynia. The vanilloid receptor VR1 (TRPV1) is expressed by nociceptors, and is triggered by capsaicin, noxious heat, protons, and chemicals produced during inflammation. In the present study we show increased papillary VR1 fibres by immunostaining and image analysis in vulvodynia tissues compared to controls (P<0.002). VR1 expression was found to be significantly increased when the percentage area immunostained was expressed as a ratio of VR1 to PGP 9.5, a pan‐neuronal marker (P=0.01). VR1‐positive fine epidermal fibres also appeared to be increased in vulvodynia tissues, by inspection. Fibres immunoreactive to the voltage‐gated sodium channel SNS1/PN3 (Nav1.8), also expressed by nociceptors, were relatively scarce in both vulvodynia and control tissues. We hypothesize that increased expression of VR1 by nociceptors could mediate some of the symptoms in vulvodynia, for which systemic or topical specific VR1 antagonists may provide novel treatment.

Increased innervation of the vulval vestibule in patients with vulvodynia

Summary Backgroundu2003Vulval vestibulitis is a condition characterized by the sudden onset of a painful burning sensation, hyperalgesia, mechanical allodynia, and occasionally pruritus, localized to the region of the vulval vestibulus. It is considered the commonest subset of vulvodynia. Pain precipitated in the absence of nociceptor stimuli might be triggered by previous peripheral nerve injury, or by the release of neuronal mediators, which set off inappropriate impulses in nonmyelinated pain fibres sensitizing the dorsal horn neurones. The pathophysiology of vulval vestibulitis is still unclear.

Src-related protein tyrosine kinases are physically associated with the surface antigen CD36 in human dermal microvascular endothelial cells.

src‐related cytoplasmic PTKs are physically and functionally associated with cell surface receptors and are involved in signal transduction. In this paper we report the identification of src‐related proteins p59 fyn , pp60c‐scr and p62 yes in human microvascular endothelial cells cultured from normal human skin and their physical association with the thrombospondin receptor CD36. Such an association represents a potential signalling pathway by which thrombospondin may regulate angiogenesis.

HYPERSENSITIVITY IN ASEPTIC LOOSENING OF TOTAL HIP REPLACEMENTS THE ROLE OF CONSTITUENTS OF BONE CEMENT

Aseptic loosening is seen in a significant proportion of cemented total hip replacements (THR). In a small subgroup of patients who suffer early loosening polyethylene debris is unlikely to be responsible. We recently reported one case of allergic contact dermatitis to N,N-dimethylparatoluidine (DMT), an accelerator used in bone cement. We have therefore investigated this using skin-patch tests to a variety of substances including metals, polyethylene and the separated individual components of Simplex cement. We studied 70 patients, 15 with aseptic loosening less than two years after THR, 25 with satisfactory long-term cemented fixation, five with infected loosening of cemented THRs and 25 awaiting hip arthroplasty. We found seven positive reactions to DMT, all of them in patients with the rapid onset of aseptic loosening. Allergy to DMT is recognized in the dental profession in respect of the denture sore mouth syndrome, and could also be an occupational hazard since some industrial glues contain DMT. Our results suggest the need for awareness of possible previous dental or occupational exposure of the constituents of bone cement. We recommend the use of skin-patch testing in high-risk cases.

The new H1 antihistamines : treatment of urticaria and other clinical problems

The new H1 antihistamines are a major therapeutic advancement in the treatment of allergic disorders such as urticaria and allergic rhinitis. Their efficacy combined with greatly reduced sedating and anticholinergic side effects makes the new class of H1 antihistamines the first-line treatment in the management of urticaria and mild angioedema. The choice of a particular low-sedating H1 antihistamine depends on pharmacokinetic considerations, the severity of the problem (systemic steroids and epinephrine are the first-line treatment for severe angioedema), and the requirement for limiting the frequency of administration. The efficacy of the new H1 antihistamines in the treatment of itch due to atopic eczema and systemic disease remains uncertain, and further controlled clinical trials are needed to elucidate their possible role in these conditions.

Systemic sclerosis associated with right ventricular cardiomyopathy

Systemic sclerosis is an uncommon multisystem disorder of unknown aetiology which predominantly affects the skin. Cardiac involvement, which is far more common than was originally realized, may affect any part of the heart but most frequently affects the left ventricular myocardium. Right ventricular dysfunction is usually associated with pulmonary vascular disease. We report a case of systemic sclerosis associated with right ventricular cardiomyopathy in whom pulmonary artery pressures were normal.

Fungal and parasitic skin infestations: an update in treatment

This review summarizes the information published in the past year on the treatment of fungal and parasitic skin infestations. The literature on fungal skin infections has been dominated by reports defining the efficacy, frequency, duration, side effects and drug interactions as well as the costs of treatment for the superficial and deep dermatophytoses. The main antifungal agents now under clinical investigation include the newly developed drugs amorolfine, terbmafme, itraconazole, fluconazole, naftifine and saperconazole. There is also renewed interest in older agents, re-defining their use and suitability with new information relating to different methods of administration. Trials have included comparisons of different vehicles to maximize efficacy and minimize side effects, including systemic treatment with liposomal amphotericin B. The search continues for the most effective therapy against the onychomycoses. From the wealth of publications in the past year, this review concentrates on three areas of therapy for parasite skin infestations; the treatment for cutaneous leishmaniasis; permethrin as a treatment for scabies; and pediculosis infestation and the use of ivermectin in treating onchocerciais.

An update on acne

This review summarizes the information published in the past year on acne and its treatment. The majority of the literature concentrates on comparing therapeutic approaches, in particular the development of the vitamin A derivatives.