Published on 18/03/2015 by admin
Filed under Dermatology
Last modified 18/03/2015
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Sally H. Ibbotson and Robert S. Dawe
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports
Chronic actinic dermatitis (CAD), previously photosensitivity dermatitis/actinic reticuloid (PD/AR) syndrome, is a chronic dermatitis (sometimes with pseudoreticuloid features) predominantly of photo-exposed sites. Objective abnormal photosensitivity (to ultraviolet B [UVB] and often UVA and visible light) is an essential component of the syndrome. It usually arises on a background of a preceding dermatitis, whether endogenous or exogenous. It always involves photoexposed sites, but half the cases also report covered site involvement. More than three-quarters have contact allergens, often multiple. It typically presents in men over the age of 50 years, but it can occur in younger patients and women. All skin phototypes can be affected.
Phototesting investigations are essential. Without investigation, definitive distinction between photoaggravated eczemas, drug-induced photosensitivity, and CAD is not possible.
Photoprotection advice should include environmental measures (use of window film to prevent UVA transmission and avoidance of single envelope compact fluorescent lamps for those with extreme UVA and visible light sensitivity), behavioral measures (including avoidance of sunlight in the middle of the day), clothing measures (tightly woven clothing, dark colors for those with visible wavelength sensitivity), and topical sunscreens. Patient education to reduce exposure to their contact allergens is necessary. Contact allergy tends to persist indefinitely, whereas photosensitivity can eventually resolve.
For active disease, use of emollients and potent/very potent topical corticosteroids is also required. Inpatient admission, with nursing behind photoprotective screens, may be necessary for acute flares, especially if causing erythroderma. Systemic corticosteroids can be used for acute flares and reduced over weeks, with continued use of topical steroids for maintenance control. If these measures do not suffice and if the patient is not too UVA sensitive, controlled use of PUVA may be appropriate. UVB phototherapy is an alternative, although in our experience patients are usually too UVB-sensitive to tolerate this. For others a variety of systemic immunosuppressants can be tried.
Phototesting (with UVB, UVA, and visible light from monochromator or broadband sources)
Provocation testing (with solar simulator or other broadband source)
Patch and photopatch tests
Consider concomitant disease
MacKenzie LA, Frain-Bell W. Br J Dermatol 1973; 89: 251–64.
Phototesting using an irradiation monochromator if available should be performed.
Kerr AC, Dawe RS, Lowe G, Ferguson J. Br J Dermatol 2010; 162: 1406–8.
Ferguson J, Ibbotson SH. Br J Dermatol 2012; 167: 214–15.
If testing shows severe photosensitivity despite topical corticosteroid therapy this can make the diagnosis, but topical corticosteroid therapy or even low-dose oral prednisolone (10 mg/day) can lead to misleading negative testing.
Dawe RS. Drugs Aging 2005; 22: 201–7.
Phototesting is required to diagnose CAD. This review gives guidance on testing where specialized facilities are not available.
Eadie E, Ferguson J, Moseley H. Br J Dermatol 2009; 160: 659–64.
Be aware that patients with CAD may be at risk from exposure to UV radiation from compact fluorescent (’energy saving’) lamps.
Frain-Bell W, Johnson BE. Br J Dermatol 1979; 101: 503–12.
Menagé H du P, Ross JS, Norris PG, Hawk JLM, White IR. Br J Dermatol 1995; 132: 543–7.
Contact allergy is common in CAD. Patch testing, repeated at intervals as indicated by history, is an essential investigation in order not to ‘miss’ new allergens. As many CAD patients are abnormally sensitive to the UVA sources used for photopatch testing, this technique may be difficult to undertake and interpret. Photopatch testing with sub-erythemal UVA doses should be undertaken.
Chew AL, Bashir SJ, Hawk JLM, Palmer R, White I, McFadden JP. Contact Dermatitis 2010; 62: 42–6.
Be aware of changing allergen patterns with alteration in exposure over time. Para-phenylenediamine reactions in CAD may have increased.
Tan AW, Lim KS, Chong WS. Photoderm Photoimmunol Photomed 2011; 27: 172–5.
Three of 26 Singaporean patients with CAD were positive for HIV.
Treatment of Skin Disease Comprehensive Therapeutic Strategies 4e
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