C052 Drug and chemical photosensitivity

C052 Drug and chemical photosensitivity

Courses El CO47 - European Group: Shave therapy for persistent venous ulcers W. Schmeller. Department Medical Photodennatology University of ...

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Courses

El

CO47

- European

Group:

Shave therapy for persistent venous ulcers

W. Schmeller. Department Medical

Photodennatology

University

of Dermatology of Luebeck, Germany

and Venereology,

Venous ulcers, especially in postthrombotic syndrome, are often resistant to compression therapy. Wound healing fails because of trophic changes with impaired microcirculation in the ulcer and in the surrounding lipodermatosclerosis. Using the shave therapy operative procedure, the wound healing is transferred from a superficial area with trophic changes to a deeper area with less trophic changes. It is performed by removing the ulcers together with the surrounding indurated tissue up to the fascia by a Schink knive. The area is covered with split skin graft. From January 1994 to December 1996 48 patients - average age 69.4 (42-87) years - with 63 recurrent or recalcitrant ulcers of many years duration were treated by shave therapy. In 38 patients the whole split skin was successfully grafted. In 10 patients between 50% and 80% of the graft was taken and complete healing took several weeks. Follow-up studies showed very favourable results over a period of up to 3 years; ulcer recurrences in the grafted areas occurred in 8 patients, of which 4 were successfully operated on again. Shave therapy is a reliable, simple and quick method for the effective treatment of persistent venous ulcers.

European Photodermatology Group: Photobiology - Abnormal Effects of UVR

ICO48

Abnormal effects of UVR

J.L.M. Hawk. St John’s Hospital,

London,

Institute

of Dermatology,

St Thomas’

UK

The photodermatoses affect around 15% of subjects living in temperate climates, and induce severe morbidity in some. A panel of experienced and extremely competent speakers will discuss the whole range of these disorders and indicate how their complexities can now be unravelled to enable accurate diagnosis, and how many of them can now be effectively treated.

Photobiology

Polymorphic light eruption, actinic prurigo and hydroa vacciniforme

P. Thomas. France Abstract not available.

0CO50

Chronic actinic dermatitis

H. du P. Menage. Lewisham Institute

of Dermatology,

Hospital St Thomas’

NHS Trust, and St John’s Hospital, London, UK

Chronic actinic dermatitis (photosensitivity dermatitis/actinic reticuloid syndrome) encompasses the conditions previously known as persistent light reactivity, photosensitive eczema, and actinic reticuloid. It is diagnosed by the clinical features and confirmed by monochromator irradiation tests which are ab-

Effects

S69

of UVR

normal in all cases. Patch and photopatch tests are important ancillary investigations as contact allergy, and rarely photocontact allergy, may preceed the development of the disease, may mimick it clinically or may complicate its evolution. Although more common in middle aged to elderly men it is also observed in women. Co-existent atopic eczema may predispose to early onset disease and CAD has been reported in association with human immunodeficiency virus infection. The pathogenesis is only partially understood. The pattern and kinetics of the evolution of the infiltrate and of adhesion molecule expression is compatible with a delayed type hypersensitivity reaction. The trigger for this response has been postulated to be an endogenous photoantigen and action spectrum studies lend indirect support to this theory. Oxidative damage has also been proposed to play a role in the disease process. Sun avoidance and sun protection is the hallmark of management in conjunction with emollients and topical steroids. Intermittent therapy with azathioprine, oral cyclosporin or PUVA is helpful in severe cases. ElCO51 Solar utticaria - Pathogenesis and

management

G.M. Murphy. Dept of Dermatology, Dublin

Beaumont

Hospital,

9, Ireland

Solar urticaria is a rare but disabling disorder characterised by itching, inflammation and whealing within minutes of sun exposure. All ultraviolet (UV) wavelengths may be incriminated, and some patients react to visible light. Some patients are shown to have a circulating factor in which leads to degranulation of mast cells on sun exposure. Unusual forms of solar urticaria include localised solar urticaria and solar vasculitis. Treatment includes antihistamines, and total sunscreens capable of protecting against precipitating wavelengths. Desensitising regimens include UVB and UVA or PUVA in increasing dosage. Plasmapheresis may rarely be required in recalcitrant disease. Relapse is usual after treatment, but occasional patients derive long-lasting benefit. I CO52 Drug and chemical photosensitivity J. Ferguson. Photobiology Unit, Ninewells Hospital and Medical

ICO49

-Abnormal

School,

Dundee

DDI

9SZ Scotland

A broad range of systemic drugs and topical chemicals are capable of sensitising the skin to ultraviolet irradiation. Frequently literature reports of new agents are of an anecdotal type. There is a need for laboratory and clinical methodology to be used to define the information required to know whether new compounds are photoactive or not. Regulatory authorities now require such data for selected groups of drugs/chemicals. In the last five years, the major new groups of systemic photosensitisers to have emerged are the fluoroquinolone antibiotics. Some such as Ofloxacin and Norfloxacin are mild sensitisers while others (Spartloxacin and Lomefloxacin) are potent sensitisers. Current photoallergens strongly feature absorbent sunscreens. Although such reactions are uncommon, suspicion indicates photopatch testing.