H. du P. Menagé

Contact and photocontact sensitization in chronic actinic dermatitis: sesquiterpene lactone mix is an important allergen

Summary Eighty‐nine patients with chronic actinic dermatitis (CAD) were retrospectively studied: 69 (78%) male and 20 (22%) female, with mean ages of 66 and 64 years, respectively; nine (10%) were dark skinned. Eight (9%) were abnormally sensitive to UVB wavelengths alone, 74 (83%) to UVB and UVA, and seven (8%) to UVB, UVA and visible radiation. Eighty‐six patients were patch tested to an extended standard European series of contact allergens, including in 80 cases a 0.1% mix of three sesquiterpene lactones, and photopatch tested to a standard photopatch series. Sixty‐four of these 86 patients (74%) had positive patch or photopatch tests; 36% (29 of 80) were sensitive to the sesquiterpene lactone mix, 21% (18 of 86) to fragrance compounds, 20% (17 of 86) to colophony, and 14% (12 of 86) to rubber chemicals. Ten (12%) had positive photopatch tests; five (6%) to musk ambrette, six (7%) to sunscreens and one to both. Fourteen of the eighty‐nine patients with CAD (16%) had preceding endogenous eczema. In 18 of 86 patients (21%), CAD occurred alone, with neither detectable contact nor photocontact allergy, nor a preceding history of endogenous eczema. This study confirms the association between Compositae (sesquiterpene lactone) dermatitis and CAD.

Guidelines for dosimetry and calibration in ultraviolet radiation therapy: a report of a British Photodermatology Group workshop

Summary This report examines the dosimetry of ultraviolet (UV) radiation applied to dermatological treatments, and considers the definition of the radiation quantities and their measurement. Guidelines are offered for preferred measurement techniques and standard methods of dosimetry. The recommendations have been graded according to the American Joint Committee on Cancer classification of strength of recommendation and quality of evidence (summarized in Appendix 5 ).

The efficacy of psoralen photochemotherapy in the treatment of aquagenic pruritus

Summary Psoralen photochemotherapy (PUVA) was effective in the treatment of five patients with aquagenic pruritus, associated in one with polycythaemia rubra vera and in another with the myelodysplastic syndrome. Relapse occurred within 2–24 weeks when treatment was discontinued. Maintenance therapy or a further course of PUVA was necessary to maintain remission. This requirement may limit the value of the therapy.

Cutaneous manifestations of tuberculosis

Cutaneous involvement is a rare manifestation of tuberculosis (TB). The correct diagnosis is often significantly delayed because cutaneous TB is not routinely considered in the differential diagnosis or because investigations fail to reveal the presence of Mycobacterium tuberculosis. The clinical features of cutaneous TB are diverse, and result from exogenous and endogenous spread of M. tuberculosis and from immune‐mediated mechanisms. The recognition of cutaneous TB is important, as the diagnosis is frequently overlooked resulting in delayed treatment.

Ultraviolet A1 phototherapy: a British Photodermatology Group workshop report

Whole‐body ultraviolet (UV)A1 (340–400 nm) phototherapy was first introduced 30 years ago, but is currently available in the UK in only three dermatology departments. A workshop to discuss UVA1 was held by the British Photodermatology Group in May 2009, the aim of which was to provide an overview of UVA1 phototherapy and its role in practice, and to identify areas in which further studies are required. The conclusions were that UVA1 phototherapy is an effective treatment in several inflammatory skin diseases, including localized scleroderma and atopic eczema (AE); however, deficiencies and limitations exist in the published evidence base. For most diseases, such as AE, other treatments also exist, which are generally more effective than UVA1. However, for some diseases, particularly morphoea, the evidence of efficacy is stronger for UVA1 than for other treatments. Acute adverse effects of UVA1 are minimal. The risk of long‐term adverse effects, particularly skin cancer, is unknown. Medium to high doses of UVA1 are needed for efficacy in most situations, but the equipment to deliver such doses is large, expensive and difficult to install. UVA1 is currently underprovided, and the recommendation of the workshop is that more tertiary centres should have access to UVA1 phototherapy in the UK.

Persistent severe amiodarone-induced photosensitivity.

Amiodarone, a benzofuran derivative, has been used therapeutically as an antiarrhythmic and coronary vasodilator in Europe since 1964. One of its commoner side effects is cutaneous photosensitivity; more rarely, after ingestion of the drug for around 12 months, a slate‐grey or violaceous discoloration of sun‐exposed sites may gradually develop. Both of these side effects usually resolve within 2 years of discontinuation of the drug. We now present a woman who developed both photosensitivity and a slate‐grey discoloration whilst taking amiodarone; on discontinuation of the drug, the dyspigmentation gradually resolved, but the photosensitivity has persisted and the patient remains symptomatic more than 17 years later.

Fish odour syndrome with features of both primary and secondary trimethylaminuria

We report a patient with the fish odour syndrome who has both primary and secondary trimethylaminuria. The diagnosis was made using biochemical and genetic analysis in the apparent absence of any characteristic smell. Differentiation of primary and secondary trimethylaminuria is usually made on urinary analysis of trimethylamine and its metabolite trimethylamine N‐oxide, with different, characteristic patterns of both compounds in primary and secondary trimethylaminuria. Our patient had biochemical analysis consistent with a diagnosis of secondary trimethylaminuria, while analysis of the flavin‐containing mono‐oxygenase 3 gene, the causative gene in primary trimethylaminuria, demonstrated three sequence polymorphisms, two of which are known to reduce enzyme activity. The patient showed temporary clinical and biochemical response to treatment with metronidazole and neomycin. It is important to be aware of this diagnosis in patients without obvious clinical signs, and of the subjective benefits of treatment.

Human T‐cell lymphotrophic virus tropical paraparesis, hyperhidrosis and Norwegian scabies

A 56-year-old West Indian man presented with a 5-year history of excess sweating and a rash affecting the trunk from a clear cut-off level below the nipples extending round to his back. He had no history of eczema or atopy. He had undergone neurosurgery in 1995 for a presumed prolapsed disc and had later been diagnosed with human T-cell lymphotrophic virus type 1 tropical spastic paraparesis (HTLV-1 TSP). He was wheelchair-bound and lived in a nursing home. He had high blood pressure and impaired glucose tolerance, and he was taking aspirin and diltiazem. On physical examination, he had prominent impetiginized eczema on the back corresponding to the area of hyperhidrosis with a clear cut-off line at the normal skin (Figs 1a,b). Results of laboratory investigations showed eosinophilia and a raised IgE level. Mycology gave negative results and skin swabs grew Staphylococcus aureus. A working diagnosis of eczema was made, in part endogenous and in part exacerbated by the hyperhidrosis. The patient was treated with emollients and potent topical corticosteroids for his eczema together with propantheline 15 mg three times daily to try to control the sweating, but he failed to respond. The patient was treated successfully with two applications of topical permethrin and an oral dose of ivermectin 200 lg ⁄ kg, and contact tracing was carried out. Neurology assessment suggested a diagnosis of Ross s syndrome to account for the patient s hyperhidrosis. This is a degenerative focal dysautonomia and peripheral nerve dysfunction, which is defined as a triad of segmental anhidrosis, hyporeflexia and tonic pupils. Most patients are troubled by the compensatory hyperhidrosis involving the face, trunk and upper limbs. It is part of a spectrum of dysautonomic disorders, is very rare and usually has a benign course, and the exact pathogenesis is not known. Norwegian scabies is seen in patients who are physically incapacitated due to a stroke or severe arthropathies, as they are unable to scratch in response to itch, so the burrows and the scabies mites are not destroyed. This is also seen in patients with skin anaesthesia secondary to sensory neuropathy or spinal injury as they do not perceive the sensation of itch. Norwegian scabies has been associated with immunosuppression and has been seen in patients with human immunodeficiency virus and HTLV-1. HTLV-1 TSP is a chronic progressing demyelinating disease with weakness and spasticity mainly affecting the legs. These factors may all have been contributory in our patient. The well-demarcated distribution of Norwegian scabies in this patient is of particular interest and reflects his segmental hyperhidrosis. Atypical presentations of scabies remain a challenge and must be considered in patients with immunosuppression and ⁄ or neurological disease. (a)

Endobronchial involvement in a patient presenting with cutaneous sarcoid

Half of all patients with cutaneous sarcoidosis will develop pulmonary disease. We report a case of cutaneous and endobronchial sarcoidosis and describe a scheme for identifying pulmonary involvement in patients with cutaneous sarcoid.