Chronic actinic dermatitis successfully treated with mycophenolate mofetil

Abstract

Chronic actinic dermatitis (CAD) is characterised by abnormal photosensitivity to ultraviolet and often visible wavelengths. The aetiology remains uncertain and the response to standard therapies is unpredictable. Mycophenolate mofetil (MMF) is an immunosuppressant which is being increasingly used for inflammatory skin disorders. We present our recent experience using this novel treatment for refractory CAD.Two male patients, aged 55 years (patient 1) and 49 years (patient 2), presented with an eczematous eruption on photo exposed skin which was present year round with significant worsening in the summer. Phototesting revealed markedly reduced 24-hour minimal erythema dose and exaggerated papular responses to UVB. Patient 1 tested positive to nickel, cobalt and dichromate on patch testing and oxybenzone and Uvistat 30 on photopatch testing. Patient 2 had positive reactions to Balsum of Peru and phosphorous sesquisulphide on patch testing. His photopatch tests were negative. Histology showed epidermal hyperplasia and a dense perivascular infiltrate in the dermis. Porphyria screen, anti-nuclear and anti-Ro antibodies were negative.Both patients had refractory CAD or developed significant side effects to conventional therapies, including prednisolone, PUVA, azathioprine and cyclosporin. They received at least 6 years of these treatments prior to commencing MMF in early 2000. Each noted a significant improvement in symptoms within six weeks and subsequent clearing of the eczematous lesions. Patient 1 requires continuous treatment with MMF 500mg twice daily to prevent relapses. Patient 2 remains in remission using MMF 1g twice daily during the spring and summer months. Both patients have tolerated the treatment well with no abnormalities in blood count or liver biochemistry. Since commencing MMF, their quality of life has significantly improved with pursuit of outdoor activities using sun protection measures.These observations suggest that MMF should be considered as an alternative treatment to conventional therapies for refractory CAD. Chronic actinic dermatitis (CAD) is characterised by abnormal photosensitivity to ultraviolet and often visible wavelengths. The aetiology remains uncertain and the response to standard therapies is unpredictable. Mycophenolate mofetil (MMF) is an immunosuppressant which is being increasingly used for inflammatory skin disorders. We present our recent experience using this novel treatment for refractory CAD. Two male patients, aged 55 years (patient 1) and 49 years (patient 2), presented with an eczematous eruption on photo exposed skin which was present year round with significant worsening in the summer. Phototesting revealed markedly reduced 24-hour minimal erythema dose and exaggerated papular responses to UVB. Patient 1 tested positive to nickel, cobalt and dichromate on patch testing and oxybenzone and Uvistat 30 on photopatch testing. Patient 2 had positive reactions to Balsum of Peru and phosphorous sesquisulphide on patch testing. His photopatch tests were negative. Histology showed epidermal hyperplasia and a dense perivascular infiltrate in the dermis. Porphyria screen, anti-nuclear and anti-Ro antibodies were negative. Both patients had refractory CAD or developed significant side effects to conventional therapies, including prednisolone, PUVA, azathioprine and cyclosporin. They received at least 6 years of these treatments prior to commencing MMF in early 2000. Each noted a significant improvement in symptoms within six weeks and subsequent clearing of the eczematous lesions. Patient 1 requires continuous treatment with MMF 500mg twice daily to prevent relapses. Patient 2 remains in remission using MMF 1g twice daily during the spring and summer months. Both patients have tolerated the treatment well with no abnormalities in blood count or liver biochemistry. Since commencing MMF, their quality of life has significantly improved with pursuit of outdoor activities using sun protection measures. These observations suggest that MMF should be considered as an alternative treatment to conventional therapies for refractory CAD.