NON-PORPHYRIC SKIN DISEASE IN THE PORPHYRIAS

White J, Creamer D, Peters TJ

 

King's College, London, UK

 

 

Although the skin manifestations of the porphyrias are well described, little attention has been paid to non-porphyric skin diseases in this group of patients.

Acne - Topical treatments for mild to moderate acne are generally safe in patients with porphyria, though there is scant evidence in the literature. Unfortunately, none of the commonly-used antibiotics are safe. Similarly, Isotretinoin, the most effective treatment for acne, is unsafe in the acute porphyrias and should be avoided.

Eczema - Eczema is often controlled with a combination of moisturizers and steroid creams or ointments. These treatments are generally safe. Moisturizers keep the skin in good condition which may help to avoid minor injuries of the skin which may lead to scarring. Anti-histamine tablets are sometimes given to help reduce itching. Chlorpheniramine (Piriton) and Promethazine (Phenergan) are considered safe. Most other antihistamines should be avoided. Considering systemic treatments for eczema, Prednisolone and Azathioprine are both safe in all forms of porphyria. Ciclosporin, another agent occasionally used to treat eczema, is not safe. For ultraviolet treatment of eczema, see below under psoriasis.

Psoriasis - Treatment with moisturizers and steroid creams/ointments is safe. Topical treatments such as Calcipotriol, Dithranol and coal tar are not known to be harmful. Systemic treatments for psoriasis include Methotrexate which must be used with caution; Acitretin and Ciclosporin are both unsafe. Ultraviolet light may be used for the treatment of both psoriasis and eczema. This may be with uv-B, or uv-A with psoralens tablets (PUVA). This treatment must be avoided in photosensitive porphyrias. Psoralens tablets are known to be unsafe in porphyria.

Skin surgery - Sometimes the skin needs to be sampled either to help make the diagnosis or to remove benign or malignant tumours. This is usually done under local anaesthetic. Most local anaesthetic agents are safe in porphyria, but Bupivacaine (Marcaine) is preferred.

Warts - Preparations such as salicylic acid (cream or paint) are safe but care should be taken since the skin in porphyria is fragile. This is also the case for cryosurgery.

Summary - Sun avoidance and general skin care measures such as the use of moisturizers are important in keeping the skin in good condition in those with cutaneous porphyrias. For skin problems unrelated to porphyria, cream/lotion treatment is generally safe. Tablet treatments can be unsafe and should be checked with the doctor prescribing the treatment. Monitoring urinary ALA and PBG may be useful in predicting a relapse to porphyrinogenic drugs