Rare Rheumatology News

Disease Profile


Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable



Parasitic diseases


Toxocariasis is a parasitic condition caused by the larvae of two species of Toxocara roundworms: Toxocara canis (from dogs) and Toxocara cati (from cats). Many people who are infected with Toxocara never develop any signs or symptoms of the condition. In those who do become sick, symptoms may present as:

  • Ocular Toxocariasis when the larvae infect the eye and cause vision loss, eye inflammation, and/or damage to the retina.
  • Visceral Toxocariasis when the larvae infect various organs of the body (i.e. the liver or the central nervous system) and cause fever, fatigue, coughing, wheezing, and/or abdominal pain.

Toxocariasis is generally spread through dirt that has been contaminated with animal feces that contain infectious Toxocara eggs. Young children and owners of dogs and cats have a higher chance of becoming infected. Visceral toxocariasis is treated with antiparasitic medications. Treatment of ocular toxocariasis is more difficult and usually consists of measures to prevent progressive damage to the eye.[1][2]


Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • You can obtain information on this topic from the Centers for Disease Control and Prevention (CDC). The CDC is recognized as the lead federal agency for developing and applying disease prevention and control, environmental health, and health promotion and education activities designed to improve the health of the people of the United States.
  • DermNet NZ is an online resource about skin diseases developed by the New Zealand Dermatological Society Incorporated. DermNet NZ provides information about this condition.
  • The Merck Manuals Online Medical Library provides information on this condition for patients and caregivers.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Toxocariasis. Click on the link to view a sample search on this topic.


  1. Parasites Toxocariasis. Centers for Disease Control and Prevention. January 2013; https://www.cdc.gov/parasites/toxocariasis/index.html.
  2. Sun Huh, MD, PhD. Toxocariasis. Medscape Reference. August 2014; https://emedicine.medscape.com/article/229855-overview#a6.