Care that is more than skin deep
THE SKIN is the largest organ in our body. In an average 70kg individual, it weighs over 5kg and covers a surface area approaching 2 sq metres.
It acts as a barrier keeping the outside world out but also functions as a sensory, endocrine and immunological organ, and helps to control body temperature.
Skin failure increases the risk of infections leading to morbidity and disability.
Ageing of the skin has an intrinsic component, due to advancing years, and an extrinsic component which is caused by exposure to ultraviolet (UV) irradiation.
The combination results in impaired barrier function because of a thinning of the upper layer of the skin ( the epidermis) and damage to the supporting collagen and elastin in the lower layer (the dermis).
This produces a condition known as dermatoporosis characterised by a thin skin which easily bruises, bleeds and tears after minor trauma.
Unfortunately at present we cannot reverse this process but better education about protection against UV rays can minimise the impact.
There is a dilemma about sun exposure. On the one hand the sun is needed for the production of vitamin D by the skin. UV irradiation also increases the production of nitric oxide which opens up blood vessels, reduces blood pressure and possibly protects against coronary artery spasm.
On the other hand, damaging effects of UV irradiation causes dermatoporosis and absorption of UV radiation induces mutations within skin cells.
These mutations may create premalignant conditions such as actinic keratoses and Bowen’s disease and eventually cause a variety of skin cancers.
Although sunlight will increase vitamin D production, it is not possible to predict how much sun exposure is required.
Public Health England recommends that adults and children over the age of one should consider taking a daily supplement containing 10mcg of vitamin D, particularly during autumn and winter if they are not often outdoors,
According to recent findings, the development of skin cancers as a result of UV exposure ( known as photocarcinogenesis) involves a cascade of processes causing various cellular, biochemical, and molecular changes closely related to each other
Exposure of the DNA within the skin cells to UV irradiation cause changes that alter the way DNA is subsequently processed.
It has also been shown to trigger immunosuppression which plays an important role in photocarcinogenesis.
The result is that after a varying time of sun exposure, hard crusted lesions (actinic keratoses) may appear, or more extensive red crusted areas (Bowen’s disease) may develop.
These are pre-malignant and although some may spontaneously regress, others can develop into more serious squamous cell carcinomas.
Treatment of the pre-malignant lesions can be undertaken using cryotherapy (freezing with liquid nitrogen) or by the application of creams such as 5-Fluorouracil, Imiquimod or Ingenol.
All these treatments kill off the abnormal cells allowing new healthy skin to grow back.
Mutations in other genes are involved in the development of malignant basal cell carcinomas and melanomas.
Basal cell carcinomas are the most common and the least serious of skin cancers as they only very rarely spread to other parts of the body (metastasize).
This is in contrast to squamous cell carcinomas that do have the potential to metastasize.
The latest 2014 statistics reveal that in that year there were more than 130,000 basal cell carcinomas and squamous cell carcinomas diagnosed in the UK, but this is considered a serious underreporting as it is not mandatory to record basal cell carcinomas.
Although very early basal cell carcinomas can be treated in the same way Different layers of the skin react in a variety of ways to UV irradiation
as pre-malignant lesions, most of these tumours and squamous cell carcinomas are excised or, less commonly, treated with radiotherapy.
For these reasons we should be on the lookout for any lesion that is itchy, changing in shape, size or colour, or bleeds. If you are concerned, consult your GP.
Cases of malignant melanoma — when a tumour arises from the pigment-producing melanocytes within the skin — have risen by 360 per cent since the late 1970s and this worrying trend continues. The mortality rates have increased by 156 per cent since the early ’70s and the lifetime risk of developing a melanoma is one in 52 for men and one in 54 for women.
As the only chance of curing a melanoma is for it to be excised at an early stage, it is crucial that self-assessment of one’s skin should be undertaken and if there are changes in the shape, outline, size or colour, or if the lesion should be itchy, sore or bleeds then it would be appropriate to seek professional advice.
There has been great excitement over the availability of new treatments for melanoma that has metastasized, but our aim should be to detect such tumours early and cure the patient by prompt excision.
Ageing skin becomes progressively drier which is due to changes in the molecular composition of the epidermal cells, most prominent of which is the reduction in the protein filaggrin.
Fillagrin acts as a natural moisturising factor, allowing hydration of the skin. The combination of this deficiency, together with the degreasing effect of soap and a centrally heated environment, may encourage the development of eczema.
This can be treated with the application of emollients and topical steroids.
An uncommon disease occurring in more mature Ashkenazi individuals is bullous pemphigoid. This can present initially with an eczema before evolving into blisters. If any itchy rash or eczema is not settling with simple treatments a professional opinion is required.
Other features of ageing skin are the appearance of brown warty growths known as seborrheic keratoses, and dotted, raised, red lesions which represent collections of blood vessels known as cherry angiomata. Both of these lesions are entirely harmless but if they get bigger or bleed it would be sensible to seek an expert opinion.
This article is an edited version of a talk given in the Jewish Care Health Insights series. Professor Malcolm Rustin is a consultant dermatologist at the Royal Free Hospital
Sun can be both an enemy and a friend to the skin