by EBSCO Medical Review Board
(Fish Scale Disease; Xeroderma)


Ichthyosis is a group of skin disorders that cause dryness and scaling. There are two main types:

  • Inherited—due to hereditary factors
  • Acquired—due to certain health problems (rare)


The inherited type is caused by a genetic defect that is passed from parent to child or that occurs on its own.

The acquired type may be caused by health problems, such as:

Risk Factors

Things that may raise the risk of this problem are:

  • Having other family members who have it
  • Having any of the health problems that may cause the acquired type


It can affect any part of the body. It is common on the legs, arms, and trunk. Symptoms can be mild to severe and include:

  • Dry, flaking skin
  • Scaling that looks like fish scales
  • Shedding of skin layers
  • Itching
  • Scarring


The doctor will ask about your symptoms and health history. You may also be asked about your family history. A physical exam will be done. It will focus on the skin.

Blood tests may be done to look for signs of the gene linked to this health problem.

Skin Biopsy
Skin proceedure
Copyright © Nucleus Medical Media, Inc.


There is no cure. The goal of treatment is to manage symptoms. Any underlying cause will also need to be treated.

Treatment may include:

  • Lifestyle changes, such as using non-soap cleansers and removing scales with a pumice stone
  • Ointment, lotions, or creams to keep the skin moist
  • Solutions or creams with lactic/salicylic acid or urea to ease scaling
  • Medicines, such as retinoids or calcipotriene to treat severe symptoms


There are no current guidelines to prevent this health problem.


Foundation for Ichthyosis & Related Skin Types 

The National Registry for Ichthyosis and Related Disorders 


Canadian Dermatology Association 

Health Canada 


Ichthyosis. EBSCO DynaMed website. Available at: Accessed March 24, 2021.

Ichthyosis. DermNet NZ website. Available at: Accessed March 24, 2021.

Newly diagnosed? Foundation for Ichthyosis & Related Skin Types website. Available at: Accessed March 24, 2021.

Schmuth M, Martinz V, et al. Inherited ichthyoses/generalized Mendelian disorders of cornification. Eur J Hum Genet. 2013 Feb;21(2):123-133.

Revision Information