Bowen's disease comes from the top layer of the skin (epidermis) and is a precancerous stage. The condition is often referred to as an intermediate stage between actinic keratosis and squamous cell carcinoma (type of skin cancer). Carcinoma in situ is another name for the same condition.
Bowen's disease occurs in both skin (most commonly) and mucous membranes, and is seen as well-defined, reddish areas with thickened, scaly skin. Occasionally a wound or crust is seen in these. The skin changes are usually medium-sized (1-5 cm).
The disease mainly occurs on sun-exposed areas (face, ears, hands and legs).
Around three percent develop further into skin cancer (ten percent if localized to the genital mucosa).
Ultraviolet light (sun) is the most important risk factor. Other risk factors are radiation, arsenic, infection of the skin/mucous membranes with the human papillomavirus (HPV) and reduced immunity.
The incidence of Bowen's disease rises with increasing age.
Bowen's disease can be treated with surgery, photodynamic therapy (PDT) and freezing therapy (cryotherapy). There is also a selection of immune-stimulating creams.