Management of skin disease
Prevention of Skin Disease
Cardinal to the pathogenesis of skin disease is the triad of:
- porphyrin accumulation
- exposure to ultraviolet light
- minor trauma
Read the following page for more details: Skin disease in porphyria. Important steps therefore in the prevention and minimisation of porphyric skin disease are the following:
Minimisation of the accumulation of porphyrins
Review all medication taken by the patient, and stop any which are not clearly safe in porphyria. This (which on theoretical grounds should include a reduction in smoking and drinking, since components of tobacco and alcoholic beverages are to a limited extent porphyrin-inducing) will help to reduce the de novo synthesis of porphyrins. This step is clearly indicated in variegate porphyria, a condition known to be aggravated by drugs (See Drug precautions in porphyria), but is less well established in porphyria cutanea tarda.
Reduction in exposure to ultraviolet light
Patient should avoid the sun as far as possible. Choice of clothing is important: clothing is a far better sunblock than most creams and lotions. Closed shoes, socks and long pants will prevent disease affecting the lower limbs. High collars and hats will protect the neck and face. Long sleeves will protect the forearms.
Conventional sunblocks are designed to filter out the short ultraviolet wavelengths (UVA) which cause sunburn. To prevent porphyria skin disease, long ultraviolet wavelengths (UVB) and even some of the visible wavelengths must be screened out. Therefore the most effective sunblocks are those which are opaque such as those containing high concentrations of zinc oxide. These are usually cosmetically unacceptable. An acceptable compromise is the use of the newer high-protection factor preparations containing micronised titanium dioxide. These are transparent but more effective in filtering out the damaging wavelengths. Sunblocks must be used correctly. They need to be applied prior to exposure, and to be reapplied frequently. In practice patients need to make a choice between a major change in lifestyle (sun avoidance and the obsessional use of clothing and sunblocks), and a more relaxed approach which may result in somewhat more severe skin disease. They should be advised to find the compromise most acceptable to them.
The occasional patient with severe, cosmetically worrying blistering and erosions is often helped by the use of opaque flesh-tinted cosmetic creams, sold at some pharmacies and department stores, where the assistant matches the cream to the patient's own complexion. These not only hide the blemishes but, being opaque, prevent further access of radiation to the skin, allowing it to heal. Not infrequently such severe disease is secondarily infected when first seen, and a course of cloxacillin or amoxicillin-clavulanate is helpful.
Extreme measures such as replacement of fluorescent lights with reddish incandescent bulbs and installation of filtering screens over windows may have a place in excessively rare circumstances such as congenital erythropoietic porphyria, but are never justified for patients with common variegate porphyria or porphyria cutanea tarda.
Avoidance of trauma
Porphyric skin disease is very prone to break down in response to minor trauma. Suitable protective gloves should be worn when carrying out activities which might result in damage to the hands, such as housework or carpentry.
Treatment of Skin Disease
Treatment of established skin disease is directed towards promoting healing and preventing secondary infection and further damage. Blisters should be carefully lanced with a sterile needle: release of the blister fluid results in a smaller scar. Wounds should be gently cleaned with soap and water. Infected lesions should be dressed with Betadine™. Avoid using astringents such as Dettol™ which may further damage the skin. Patients should avoid using adhesive plaster as removal of plaster may result in further damage to the skin. Patients with severely infected lesions may require a course of systemic antibiotics such as cloxacillin or amoxicillin-clavulanate.
Porphyria Cutanea Tarda
Porphyria cutanea tarda is treatable (See Porphyria cutanea tarda). In addition to the general measures measured above, skin disease will improve with control of the underlying porphyria by venesection and chloroquine therapy (See Management of porphyria cutanea tarda).
Specific measures for the treatment of the skin disease of erythropoietic protoporphyria include beta-carotene therapy (See Erythropoietic protoporphyria).