Structure and Function of Skin
The skin is the biggest organ in the human body. An adult has an average of 1.5 to 2.0 m2 of skin, weighing 15-20 kg. Skin protects us from the direct influences of the outside world, such as UV light from the sun, and also bacteria and fungi. All kinds of good bacteria and fungi live on the skin, where they help to stop pathogenic bacteria growing. If the skin is broken, as a result of eczema or a burn, for example, this protective effect is reduced.
The skin also helps keep body temperature and fluid levels stable. The millions of nerve endings in the skin allow us to feel touch, temperature, pain and itching. The skin also produces vitamin D, which is important for bone formation. Connective tissue acts as a layer of insulation, and stores energy, as well as providing protection from impact.
Psoriasis and Eczema
Layer of bacteria
Common skin conditions with which we are all familiar include warts and acne as well as the disease skin cancer. There are in fact more than 2000 skin conditions. Psoriasis is a common condition that causes red patches and excessive flaking as a result of rapidly dividing skin cells. Eczema also causes flaking, and intense itching. Both these conditions have a major impact on quality of life. They are caused by a combination of environmental factors and a genetic predisposition that disrupts the skin microbiome (the good bacteria that live on the skin), or the skin’s defence mechanism.
The skin itself is part of the immune system and also contains immune cells that destroy harmful bacteria. Researchers at the Antoni van Leeuwenhoek Hospital and Utrecht University have researched the role of the skin’s immune cells. A genetic defect in the immune system can also cause inflammatory skin conditions.
Patients with mild symptoms can often be treated with ointments or creams. There are few other treatment options, unfortunately, though researchers continue to seek new treatment methods and investigate the predictability of treatment outcomes. Studies are also underway examining how the effectiveness of treatments such as light therapy and systemic therapy weighs up against the cost and effort involved (efficiency).
ZonMw funds research, under the Allied Healthcare Professions programme, into the further optimisation of care for patients with constitutional eczema, to allow them to manage their condition better themselves, and to gain and maintain control over their symptoms. This can greatly improve their quality of life.
Skin cancer precursor
A special study has examined the entire skin of more than 2000 residents of the Netherlands aged 50 and over. It revealed that almost 1.4 million people in this country (aged 50 and over) have one or more actinic keratoses, which are precursors for skin cancer. Actinic keratoses are scaly patches of skin caused by prolonged sun damage. This is a common skin condition, which can lead to cancer.
A study of the four most commonly used treatments for actinic keratosis found that treatment with fluorouracil (5-FU, or Efudix) cream offers the best chance of a cure, and also costs the least. Furthermore, this cream had the highest scores for patient satisfaction, and produced the greatest improvement in quality of life. A follow-up study looked at how the findings of the research could be introduced into general practice.
Basal cell carcinoma (BCC) is the most common type of skin cancer. One in five or six people in the Netherlands develops BCC. 30% of people with BCC develop another tumour within five years of the first. Researchers at Erasmus Medical Centre have developed a model that can predict whether someone will develop skin cancer more than once.
BCC is diagnosed by taking a biopsy (a skin sample). This is painful, however, and the sample has to be examined under a microscope. As a result, diagnosis takes one to two weeks. A clinical study explored a painless alternative which involves imaging the skin using a scanner. The doctor can then make a diagnosis within a few minutes, and quickly start treatment. The costs are also lower. The study found that this method is no less effective than the biopsy method. In around two-thirds of patients it was not necessary to perform a skin biopsy.
Melanoma is a rare but aggressive form of skin cancer, which often metastasises (spreads to other parts of the body). Over the past five years the treatment of metastasised melanoma has been greatly improved with the introduction of immunotherapy. Immunotherapy helps the immune system to destroy cancer cells, but it is very expensive and produces severe side-effects in around 40% of patients.
A special register (DMTR), part of ZonMw’s Effective Use of Medicines programme, keeps a record of the results of treatment in all patients with metastasised melanoma. This gives an idea of whether and which treatments have the desired effect. The side-effects of medicines are also recorded, and an estimate of costs can be made. This will eventually produce a picture of the efficiency of different treatments.
We provide grants, in collaboration with the Brandwondenstichting (Burns Foundation) for research into the treatment of burns and how to improve the quality of life of people with burn scars.
Burns damage the skin, which can no longer provide protection in the place where it is damaged. Deep second-degree and third-degree burns take a long time to heal, leading to a risk of infection. The presence of bacteria in a wound hampers healing and can lead to all kinds of complications, and longer periods of hospitalisation. Treatment with antimicrobials such as antibiotics and creams is not enough. One alternative is to use cold plasma, a kind of gas containing active particles that kill bacteria but do not affect the skin cells.
Burns and scarring
Third-degree burns produce scarring and the skin is so damaged that it cannot repair itself. Research projects have examined the effects of transplanting skin grown in the lab using tissue engineering methods, and also using the patient’s own fat. This ensures more elasticity, less adhesion and it represents a cosmetic improvement.
Living with burns
Burns have a severe physical, psychological and social impact. Patients must learn to live with scars, an altered appearance and functional impairment. The goal of the Leading Specialist Burns Care project (part of the Leading Specialist Care and Research programme) is to achieve the best possible quality of life and reintegration into society for every individual patient. It has a strong focus on after-care and self-management.