Symptoms: how do you recognise seborrheic keratosis?1, 2, 3

Seborrheic keratosis occurs as warty-like excrescences, with a scaly appearance. For this reason they are also called seborrheic warts. Seborrheic keratoses are either flesh coloured, or brown or black. In some cases, seborrheic keratosis has a crusty appearance and can be itchy. Round or oval in shape, seborrheic keratosis can appear anywhere on the body, but it most often develops on the face (especially the temples), scalp, chest and back. Seborrheic keratoses are unsightly, especially if large. The size of the keratoses can vary from 0.5 cm to several centimetres. 

What causes seborrheic keratosis?1, 2

The cause of seborrheic keratoses is unknown. In some cases, they may be linked to genetic mutations. This means that some people are genetically predisposed to developing seborrheic keratosis. Age can also a factor as seborrheic keratoses are more common after the age of 50. 

Is seborrheic keratosis serious?2

Seborrheic keratosis develops slowly. It is a benign skin lesion that never develops into cancer. 

Is seborrheic keratosis contagious?2

Although it looks like a wart, seborrheic keratosis is not a contagious lesion. It cannot spread from person to person. 

How do you get rid of seborrheic keratosis?1, 2, 3, 4

Since seborrheic keratoses are benign lesions, they do not need to be treated. However, treatment should be considered if the seborrheic keratosis is irritated, unbearably itchy or if it is unsightly. In most cases, seborrheic keratoses are removed with liquid nitrogen (cryotherapy). Other treatments are available for their removal such as shaving, laser, or surgical curettage or removal for larger seborrheic keratoses. 

Liquid nitrogen cryotherapy
This method involves applying liquid nitrogen to the wart to freeze it and then dislodging it from its base. The doctor soaks a cotton bud in liquid nitrogen from a container before placing the bud twice on the wart for about ten seconds. A spray that delivers nitrogen from a pressurised container can also be used. The nitrogen is kept on the area for around twenty seconds. 

Cryotherapy for seborrheic keratosis can be effective from the very first application. But in most cases, several sessions are needed to get rid of it completely. 

After a cryotherapy session, the treated area may be red, swollen and a blister may form. After a few days, the scab that has formed will eventually drop off. You should not remove this scab, as it may cause an unsightly scar.  

Surgical curettage and removal
Surgical curettage and removal (excision of the lesion) performed under local anaesthetic are techniques only used for large seborrheic keratitis. Patients may experience painful scarring after the curettage procedure. 

Shaving consists of scraping off the seborrheic keratitis on the surface of the skin with a small electric scalpel or blade. This technique is performed under local anaesthetic. 

A Q-Switched or a CO2 laser can also be used to remove seborrheic keratitis. 

  1. Seborrheic Keratoses, MSD Manual, January 2022 (article consulted on 29 November 2023).  
  2. Kératose séborrhéique [Seborrheic keratosis], Chirurgie dermatologique Paris Monceau (article consulted on 29 November 2023).  
  3. Comment se débarrasser de ses acrochordons, verrues séborrhéiques et grains de beauté ? [How do you get rid of skin tags, seborrheic keratitis and moles], Dr Mayeux, esthétique médicale et laser (article consulted on 29 November 2023).    
  4. Verrues : la consultation et le traitement [Warts: consultation and treatment],, 26 September 2022 (article consulted on 29 November 2023).  
auteur: Annabelle Iglesias
Annabelle Iglesias
Health Journalist
A graduate of ESJ Pro, Annabelle Iglesias is a freelance journalist specializing in health and well-being. She primarily writes on health and nutrition topics.