National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Porokeratosis of Mibelli

Porokeratosis of Mibelli is a skin condition that usually develops in children or young adults.  It begins as one or a few small, brownish bumps that grow into raised, bumpy patches.  These patches slowly increase in size over time.  The cause of this condition is unknown, though exposure to sunlight or other forms of radiation, genetic factors and a weakened immune system have been suggested as possible risk factors.  Porokeratosis of Mibelli may sometimes harm normal tissue underlying the affected area; it may also develop into skin cancer.  Treatment depends on the size, location, and aggressiveness of porokeratosis in each affected individual; it may include observation only, medication, or surgery.[1]
Last updated: 8/24/2012

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Aplasia/Hypoplasia of the skin
Absent/small skin
Absent/underdeveloped skin
[ more ] 		0008065
Hyperkeratosis 0000962
Porokeratosis 0200044
30%-79% of people have these symptoms
Cutaneous photosensitivity
Photosensitive skin
Photosensitive skin rashes
Photosensitivity
Sensitivity to sunlight
Skin photosensitivity
Sun sensitivity
[ more ] 		0000992
Neoplasm of the skin
Skin tumors
Tumor of the skin
[ more ] 		0008069
Pruritus
Itching
Itchy skin
Skin itching
[ more ] 		0000989
Percent of people who have these symptoms is not available through HPO
Abnormality of chromosome stability 0003220
Autosomal dominant inheritance 0000006
Middle age onset 0003596
Parakeratosis 0001036
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Last updated: 7/1/2020
Treatment depends on the size, location, and aggressiveness of porokeratosis of Mibelli.  Affected individuals are recommended to visit their personal physician regularly to watch for signs of skin cancer, limit sun exposure to the affected area, and use moisturizers as needed.[2]  Imiquimod cream has been found to be an effective treatment, as has 5-fluorouracil cream.  A group of medications called retinoids (including acitretin and isotretinoin), as a pill or cream, may be another treatment option.[2]  If a skin cancer develops from porokeratosis of Mibelli, surgery is recommended.[1]
Last updated: 8/24/2012
Typically, if porokeratosis of Mibelli is not treated, it will continue to increase in size slowly.  In some adults, porokeratosis of Mibelli can arise and grow rapidly.  There is a small chance that porokeratosis could give rise to a skin cancer.[1]
Last updated: 8/21/2012

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
The main differential diagnoses are psoriasis, actinic keratosis, elastosis perforans serpiginosa, annular lichen planus, circumscribed palmoplantar hypokeratosis, focal palmoplantar keratoderma and Bowen's disease.
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • The Centers for Mendelian Genomics program is working to discover the causes of rare genetic disorders. For more information about applying to the research study, please visit their website.
  • ClinicalTrials.gov lists trials that are related to Porokeratosis of Mibelli. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

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

  • DermNet New Zealand is an online resource about skin diseases developed by the New Zealand Dermatological Society Incorporated. DermNet NZ provides information about this condition.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • 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 Porokeratosis of Mibelli. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • What is porokeratosis of Mibelli?  Does it spread to other parts of the body?  Can it turn malignant?  How is it treated?  What is the disease course without treatment?  Can it be transmitted to others?  If so, how is it transmitted? See answer


  1. Spencer LV . Porokeratosis. Medscape Reference. May 30, 2012; http://emedicine.medscape.com/article/1059123-overview#a0101. Accessed 8/21/2012.
  2. Sertznig P, von Felbert V, Megahed M. Porokeratosis: present concepts. Journal of the Academy of Dermatology and Venereology. 2012; 26:404-412. http://www.ncbi.nlm.nih.gov/pubmed/21929548. Accessed 8/16/2012.