Bowen's disease is a growth of abnormal cells that is confined to the outer layer of the skin

Bowen’s disease is a growth of abnormal cells that is confined to the outer layer of the skin.  It usually appears as a slow-growing red and scaly patch. Occasionally it can turn into true skin cancer.  For this reason, dermatologists usually treat or at least keep an eye on Bowen's disease.

It is thought to develop partly as a result of long-term sun exposure. Bowen's disease is not infectious or due to an allergy.

Bowen’s disease is not hereditary, but some of the things that increase the risk of getting it, such as a fair skin and a tendency to burn in the sun, do run in families.

What are its symptoms?

Often there are no symptoms although the surface crusting may catch on clothing.

What does it look like?

A patch of Bowen’s disease starts as a small red scaly area, which grows very slowly.  It may reach a diameter of a few centimetres across.  The commonest site is the lower leg, mainly in women.  About a fifth of women with it have more than one patch.  After many years, a small minority of patches - perhaps about 1 in 50 - turn into a type of skin cancer (a squamous cell carcinoma).  An ulcer, or a small bump, coming up on the original patch of Bowen’s disease, can signal this change.

How will it be diagnosed?

A patch of Bowen’s disease can look rather like other skin conditions, such as psoriasis.  For this reason a biopsy may be needed to make the diagnosis.

Can it be cured?

Yes, there are a variety of ways in which this can be achieved (see below). 

How can it be treated?

Several treatments are available for Bowen’s disease, such as freezing it, scraping it off the skin (curettage), and surgical removal.  In some cases a cream known as 5-fluorouracil (Efudix cream) or an alternative cream called imiquimod (Aldara) may be used.  Photodynamic therapy is available in some clinics now (see below). Radiotherapy (X-ray treatment) is being used less often.  

However a particular problem is that Bowen’s disease is usually found on the lower leg - where the skin is often tight and sometimes quite fragile, especially in older patients.  Healing there is slow.  Many factors, therefore, play a part in selecting the right treatment:

• The size and thickness of the patch. 
• The number of patches.
• The presence of swelling of the legs.
• The general state of the skin on the legs.

If your patch is judged to be thin and not troublesome, your dermatologist may simply suggest that it is kept under observation in a clinic, or in some cases by yourself or by your GP.

Treatment details:

• Freezing – this is done in the clinic.  It causes redness, puffiness, blistering or crusting, and may be slow to heal.  It can be done in stages for large areas of Bowen's disease.
• Curettage – this is scraping off the abnormal skin under a local anaesthetic.  The area then heals with a scab, like a graze.
• Excision (cutting the patch out) – is done under local anaesthetic.  Usually it involves stitching the skin.
• Efudix cream – this is a cream that may control or eradicate the disorder.  There are various different ways of using it, and, if it is felt to be the best treatment, the doctor who sees you will explain these to you.  Efudix works by killing the abnormal skin cells.  This means that the skin will become red and look worse during treatment, and will then heal after the end of the course of treatment, once the abnormal cells have gone.
• Imiquimod cream  - originally developed for the treatment of genital warts imiquimod cream has been found useful in treating Bowen’s disease. It also causes redness of the skin during treatment.
• Photodynamic therapy – A chemical is applied to the skin that makes the cells in the patch of Bowen’s disease sensitive to particular wavelengths of light. Light from a special lamp is then shone on the lesion.  The treatment can be associated with pain and inflammation.

Web: www.emedicine.com/derm/topic59.htm