What Is Bowen's Disease?

In most cases, Bowen's disease develops slowly and can be treated effectively. However, it is still important to have it properly assessed, as a small proportion of cases can progress to invasive squamous cell carcinoma if left untreated.

Understanding Bowen's disease

Bowen’s disease develops when abnormal squamous cells grow within the epidermis, the surface layer of the skin. These cells have undergone early cancerous changes but remain confined to this outer layer, meaning they have not yet invaded deeper tissues. For this reason, it is often described as squamous cell carcinoma in situ, or a very early form of skin cancer. The term “in situ” means “in its original place,” highlighting that the abnormal cells are contained within the top layer of the skin and have not spread beyond it.

Because the abnormal cells are limited to the surface, the condition typically grows slowly and may remain stable for some time. However, without treatment, there is a risk that it can progress into an invasive squamous cell carcinoma, where the cancer cells spread into deeper layers of the skin.

It can appear anywhere on the body, although it is often found on areas with long-term sun exposure, such as the lower legs, head, neck, arms, and hands. It can also occur in less sun-exposed areas, including the genital region, although this is less common.

Knowing where Bowen's disease sits within the wider spectrum of skin cancer can help patients make sense of their diagnosis. If the condition progresses or if another form of skin cancer is diagnosed, an appropriate approach to skin cancer treatment may depend on the type of cancer, its location, and whether it has grown beyond the surface layer of the skin.

What Bowen's disease looks like

Bowen's disease often appears as a red, scaly patch of skin. It may look dry, crusted, inflamed, or slightly raised.

Because it can resemble eczema, psoriasis, or a persistent area of irritation, it may not be recognised immediately. The patch may slowly enlarge over time and can sometimes become sore, itchy, bleed, or form a small ulcer.

It is typically slow-growing and may remain present for months or even years without resolving.

A key feature is persistence. A patch that does not heal, keeps returning, bleeds, crusts, or changes in appearance should be assessed by an appropriate healthcare professional.

Why Bowen's disease develops

The exact cause is not always clear, but long-term exposure to ultraviolet (UV) radiation is one of the main risk factors.

Other factors may include ageing, previous radiotherapy to the skin, a weakened immune system, and, rarely, previous exposure to arsenic. In some cases, Bowen's disease affecting the genital area may be linked with certain strains of the human papillomavirus (HPV).

Having Bowen's disease does not mean someone has done anything wrong. It often reflects cumulative changes in the skin that have developed over many years of sun exposure or other risk factors.

Why Bowen's disease should not be ignored

Bowen's disease is usually slow-growing, but it still needs proper assessment because the abnormal cells are already cancerous, even though they remain confined to the surface layer of the skin.

In many cases, treatment is straightforward, especially when the patch is identified before it has changed or become invasive. However, leaving Bowen's disease untreated can make it harder to know whether the abnormal cells have remained in place or begun to grow deeper.

The risk of progression to invasive squamous cell carcinoma is relatively low, but it is not zero. This is why Bowen's disease is usually treated or monitored rather than dismissed as a harmless rash.

Persistent red, scaly, crusted, or changing patches should not simply be assumed to be dry skin or irritation without medical assessment.

How Bowen's disease is treated

Treatment depends on the size, location, thickness, and number of patches, as well as the person's general health and how well the skin is likely to heal.

Common treatments may include:

• Cryotherapy, which freezes the affected area
• Prescription creams such as 5-fluorouracil or imiquimod
• Curettage, where the area is gently scraped away under local anaesthetic
• Surgical excision
• Photodynamic therapy
• Radiotherapy in selected cases

The choice of treatment depends not only on the characteristics of the lesion but also on the area of skin involved and the person's overall health. For example, treatment on the lower legs may differ from treatment on the face because healing can sometimes be slower. The aim is to remove or destroy the abnormal cells while preserving as much healthy skin as possible.

There is no single treatment that is right for everyone, which is why treatment decisions are individualised after careful assessment.

When further assessment may be needed

Bowen's disease should be assessed if the patch is changing, bleeding, becoming painful, ulcerating, or growing more quickly.

These changes do not automatically mean invasive cancer has developed, but they may indicate that further examination or biopsy is needed. A biopsy allows the tissue to be examined under a microscope and can help determine whether the abnormal cells remain confined to the surface or have become invasive.

People with a history of Bowen's disease may also have sun-damaged skin elsewhere, so ongoing skin awareness is important. New, persistent, or changing lesions should not be ignored.

When specialist oncology advice may be appropriate

Most cases of Bowen’s disease are managed by dermatologists or specialist skin cancer teams. If invasive squamous cell carcinoma, melanoma, or another more complex skin cancer is diagnosed, care may involve a wider multidisciplinary cancer team, which can include oncology specialists.

This is particularly true when treatment may involve radiotherapy, immunotherapy, targeted therapies, systemic cancer treatments, or when patients would like a second opinion about the recommended approach.

Understanding the available treatment options and why they have been recommended can help patients feel more confident when making decisions about their care.

About Dr James Wilson

Bowen’s disease is usually managed within dermatology, but it can lead to wider questions about skin cancer risk, treatment, and when specialist oncology input may be appropriate.

Dr James Wilson is a consultant clinical oncologist in private practice in London, specialising in melanoma and skin cancer. His work includes advanced radiotherapy, immunotherapy, targeted treatments, and systemic cancer care. He supports patients in understanding their options and making informed decisions about their treatment.