What is Seborrhoeic keratosis?
Seborrhoeic keratosis is a common, harmless skin growth. It can also be known as basal cell papilloma, senile wart, brown wart, age spots or barnacle.
It is a common sign of skin ageing, appearing in many adults from 40s onwards.
They can appear almost anywhere on the skin, and appear in varying numbers, from one, to hundreds. It is a degenerative condition where more keratoses appear with age.
What are the symptoms of Seborrhoeic keratoses ?
Seborrhoeic keratoses can have a similar appearance to warts, moles, actinic keratoses, or melanoma. They usually start as small, rough bumps, then thicken to have a waxy, warty surface. They can appear to stick on the skin, like a barnacle, or can have the appearance of melted wax.
Although most are a tan or brown colour, they can range in colours from white to black.
They can appear almost anywhere on the skin except the palms and soles of feet.
The number, and size of keratoses will also vary from one person to another.
What causes Seborrhoeic keratoses?
It is not known exactly what causes seborrhoeic keratoses. Despite the name, they are not formed from the sebaceous glands, nor are they associated with sebum.
There has been research linking sebhorrheic keratoses to sun exposure, but this is not yet proven.
Some drugs used to treat cancer such as Epidermal growth factor receptor inhibitors can result in an increase in number of keratoses. Pregnancy and oestrogen replacement therapy can also result in more growths.
Seborrhoeic keratoses are age related and degenerative in nature. They usually appear from middle age onwards, and rarely appear in children.
They are not contagious and although more keratoses may appear with age, it is not possible to spread them from one part of the body to another.
Who is at risk of Seborrhoeic keratoses?
Seborrhoeic keratoses is very common, and naturally develops with age. An estimated 90% of adults over 60 years of age has at least one keratosis. They affect older people equally regardless of race or gender.
There is a tendency for high numbers of seborrhoeic keratoses to run in families.
How does a dermatologist diagnose Seborrhoeic keratoses ?
A Dermatologist will diagnose seborrhoeic keratosis through physical examination and they may use a dermatascope which is a magnification device used by Dermatologists for skin assessments.
If there is any doubt, or any suspicion of skin cancer, then they may wish to carry out a skin biopsy to send to the laboratory for testing.
How does a dermatologist treat Seborrhoeic keratoses ?
Seborrhoeic keratoses are common and harmless, therefore most of the time they do not need treatment.
However if they are causing physical or emotional discomfort, or they are difficult to distinguish from skin cancer, it is possible for a dermatologist to remove them using a range of techniques.
Cryosurgery: Liquid nitrogen is applied using a targeted tip to the area. This freezes the growth which proceeds to fall off within a matter of days. Sometimes this causes blistering and consequent crusting which will ease within a week. Repeat treatment is typically required.
Electrosurgery (hyfrecator) or Curettage and cautery: Electrosurgery involves using an electric current (hyfrecator) to burn the growth. A curette, a scoop-shaped instrument, is then used to scrape off the treated growth. Sometimes the patient needs only electrosurgery, or just curettage.
Surgical removal: A surgical dermatologist may surgically remove the lesion either with through a shave biopsy, or broader excision.
Photodynamic keratosis (PDT): For larger areas a Dermatologist may use PDT treatment to treat the area.