This article on Epainassist.com has been reviewed by a medical professional, as well as checked for facts, to assure the readers the best possible accuracy.

We follow a strict editorial policy and we have a zero-tolerance policy regarding any level of plagiarism. Our articles are resourced from reputable online pages. This article may contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.

The feedback link “Was this Article Helpful” on this page can be used to report content that is not accurate, up-to-date or questionable in any manner.

This article does not provide medical advice.


3 Rare Skin Diseases You’ve Probably Never Heard Of

There are millions of people worldwide who live with at least one skin condition. Most people are usually familiar with common skin conditions like eczema, acne, and rosacea. In fact, most people typically have one of these common skin conditions. However, there are numerous forms of rare to very rare skin conditions that most people do not know about. These rare skin conditions can range from being mild to life-threatening. In many cases, they also affect the quality of life of the people who have them. Here are some of the rarer skin diseases you have probably never heard of.

3 Rare Skin Diseases You've Probably Never Heard Of

3 Rare Skin Diseases You’ve Probably Never Heard Of

Hidradenitis Suppurativa

Hidradenitis Suppurativa (HS) is a type of chronic inflammatory skin condition that causes lesions to form on those parts of the body where the skin touches the skin.(1,2,3) These lesions may take on many forms, including tiny pimple-like bumps, boils, or deeper acne-like nodules. Even though hidradenitis suppurativa is not classified as a form of acne, it is sometimes still referred to as acne inversa.(4,5)

The most common parts of the body where these breakouts occur include:

  • Underarms
  • Upper thighs
  • Buttocks
  • Groin
  • Breasts

The lesions caused by hidradenitis suppurativa are usually painful, and once these lesions heal, tracts and scars can develop under the skin. Hidradenitis suppurativa is a chronic and progressive condition, which means that it worsens over time, and if left untreated, it can impact the quality of life.(6)

This rare condition affect nearly two percent of the population.(7) Hidradenitis suppurativa is most commonly observed in people who smoke or are overweight. As compared to men, women are over three times more likely to develop hidradenitis suppurativa.(8) The immune system and genetics are believed to be some of the factors responsible for determining who develops this disease.

One of the main symptoms of hidradenitis suppurativa is the development of a painful skin breakout that occurs on the following parts of the body:

  • Under the breasts
  • Inner thighs
  • Between the buttocks
  • Anus
  • Groin
  • Armpits

Other symptoms of hidradenitis suppurativa include:

  • Boils
  • Deep cysts or nodules
  • Red, pimple-like bumps
  • Pain
  • Nodules that drain or leak

If left untreated, over a period of time, hidradenitis suppurativa can worsen, and you may also develop the following:(9)

  • Scars that thicken
  • Bumps that burst and leak out a bad-smelling pus
  • Painful, deep breakouts that tend to come and go
  • Tunnels, which are channels or tracts that connect the lumps and develop under the skin
  • Infections
  • Scars that develop as persistent breakouts

The hidradenitis suppurativa lesions tend to come and go, but many people may continue to always have breakouts on the skin.

There are certain factors that may worsen your condition. These include:

People with hidradenitis suppurativa are also at an increased risk for developing certain comorbidities or conditions, including:(10)

Follicular occlusion tetrad (a group of inflammatory skin conditions that include dissecting cellulitis of the scalp, acne conglobata, and pilonidal sinus disease)

Currently, there is no cure for hidradenitis suppurativa, but there are various treatment options that can help you manage the symptoms of the condition. Some of the treatment options include:

  • Hormone therapy
  • Anti-inflammatory drugs like injectable biologics
  • Topical ointments

In more severe cases, surgery might be recommended.

The lesions or bumps that develop in people with hidradenitis suppurativa usually get mistaken for boils, pimples, or folliculitis. It is possible to recognize a breakout of hidradenitis suppurativa because it usually causes bumps or lesions on both sides of the body. These bumps also tend to reoccur in the same locations, such as the groin and armpits.(11)

Medical experts are still not sure about what exactly causes hidradenitis suppurativa. However, what is known is that this disease is not contagious and is not caused by any type of underlying infection or poor hygiene. Nearly one-third of people with hidradenitis suppurativa have a family history of the condition, which suggests that there could be a genetic link.(12)

Some studies have analyzed certain mutations on specific genes and have found a connection to hidradenitis suppurativa, but more research is still needed to establish a firm link.(13)

Inverse Psoriasis or Intertriginous Psoriasis

Also known as intertriginous psoriasis, inverse psoriasis is a skin condition that is similar to hidradenitis suppurativa. In this condition, red lesions develop on parts of the body where the skin rubs against the skin. However, unlike in hidradenitis suppurativa, these lesions do not appear like boils. They are shiny and smooth.(14)

Most people with inverse psoriasis also have one other type of psoriasis that affects another part of their body. While experts are not really sure about what causes psoriasis, but the immune system and genetics are believed to be major contributing factors. Psoriasis is known to affect around three percent of people worldwide, and nearly three to seven percent of people with psoriasis also have inverse psoriasis.(15,16)

Treating inverse psoriasis can be difficult because the skin in these high-friction parts of the body is quite sensitive. Topical ointments and steroid creams are effective in the treatment of inverse psoriasis, but they can also cause painful irritation if they are overused.

People who have a more severe case of inverse psoriasis may need to be treated with ultraviolet B (UVB) light therapy or with injectable biologics for managing their symptoms.(17)

Morgellons Disease

Morgellons disease is another rare skin disease in which small fibers and particles start coming out from skin sores. This gives a sensation like something is crawling on the skin.(18) There is very little known about Morgellons disease, but according to estimates by the Morgellons Research Foundation, it affects over 14,000 families worldwide.(19)

This skin disease is most prevalent in middle-aged white women, but it is also closely linked with Lyme disease. Many doctors believe that it is a psychological condition because the symptoms of Morgellons disease are similar to those of a mental health condition known as a delusional infestation.

The symptoms of Morgellons disease are painful, but they are not life-threatening. Some of the common symptoms include:

  • Itchy skin rashes
  • Itchy skin sores
  • Black fibrous material emerging from the skin – it is present both in and on the skin.
  • Anxiety and depression
  • Fatigue

Lesions tend to affect only one specific area, either the head, the trunk, or the extremities.

Since this disease is not completely understood, there is no standard treatment regimen for this condition. People with Morgellons disease are usually advised to stay in close contact with their doctor and medical team and seek treatment for symptoms of the disease, especially depression and anxiety.


If you have a rare skin condition like the ones discussed here, it is important to take your symptoms seriously and seek treatment. If left untreated, your condition may worsen, and it may become even more challenging to treat the disease as time passes. Consult your doctor, who may refer you to a dermatologist. A dermatologist is a specialized skin doctor who can help you get to reach a diagnosis and determine the best treatment option for your condition. Remember, the earlier your medical condition is diagnosed, the earlier you can begin treatment and get relief from your symptoms.


  1. Jemec, G.B., 2012. Hidradenitis suppurativa. New England Journal of Medicine, 366(2), pp.158-164.
  2. Revuz, J., 2009. Hidradenitis suppurativa. Journal of the European Academy of Dermatology and Venereology, 23(9), pp.985-998.
  3. Alikhan, A., Lynch, P.J. and Eisen, D.B., 2009. Hidradenitis suppurativa: a comprehensive review. Journal of the American Academy of Dermatology, 60(4), pp.539-561.
  4. Jansen, T. and Plewig, G., 1998. Acne inversa. International journal of dermatology, 37(2), pp.96-100.
  5. Jansen, T., Altmeyer, P. and Plewig, G., 2001. Acne inversa (alias hidradenitis suppurativa). Journal of the European Academy of Dermatology and Venereology, 15(6), pp.532-540.
  6. Schlapbach, C., Hänni, T., Yawalkar, N. and Hunger, R.E., 2011. Expression of the IL-23/Th17 pathway in lesions of hidradenitis suppurativa. Journal of the American Academy of Dermatology, 65(4), pp.790-798.
  7. Alikhan, A., Sayed, C., Alavi, A., Alhusayen, R., Brassard, A., Burkhart, C., Crowell, K., Eisen, D.B., Gottlieb, A.B., Hamzavi, I. and Hazen, P.G., 2019. North American clinical management guidelines for hidradenitis suppurativa: A publication from the United States and Canadian Hidradenitis Suppurativa Foundations: Part I: Diagnosis, evaluation, and the use of complementary and procedural management. Journal of the American Academy of Dermatology, 81(1), pp.76-90.
  8. Kidshealth.org. 2020. A To Z: Hidradenitis (For Parents) – Nemours. [online] Available at: <https://kidshealth.org/Nemours/en/parents/101532.html> [Accessed 15 December 2020].
  9. Slade, D.E.M., Powell, B.W. and Mortimer, P.S., 2003. Hidradenitis suppurativa: pathogenesis and management. British journal of plastic surgery, 56(5), pp.451-461.
  10. Von der Werth, J.M. and Jemec, G.B.E., 2001. Morbidity in patients with hidradenitis suppurativa. British Journal of Dermatology, 144(4), pp.809-813.
  11. Saunte, D.M.L. and Jemec, G.B.E., 2017. Hidradenitis suppurativa: advances in diagnosis and treatment. Jama, 318(20), pp.2019-2032.
  12. Ingram, J.R., 2016. The genetics of hidradenitis suppurativa. Dermatologic clinics, 34(1), pp.23-28.
  13. Conditions, G., 2020. Hidradenitis Suppurativa: Medlineplus Genetics. [online] Medlineplus.gov. Available at: <https://medlineplus.gov/genetics/condition/hidradenitis-suppurativa/> [Accessed 15 December 2020].
  14. Syed, Z.U. and Khachemoune, A., 2011. Inverse psoriasis. American journal of clinical dermatology, 12(2), pp.143-146.
  15. Ifpa-pso.com. 2020. [online] Available at: <https://ifpa-pso.com/wp-content/uploads/2017/01/Brochure-Psoriasis-is-a-serious-disease-deserving-global-attention.pdf> [Accessed 15 December 2020].
  16. Guglielmetti, A., Conlledo, R., Bedoya, J., Ianiszewski, F. and Correa, J., 2012. Inverse psoriasis involving genital skin folds: successful therapy with dapsone. Dermatology and therapy, 2(1), p.15.
  17. Brune, A., Miller, D.W., Lin, P., Cotrim‐Russi, D. and Paller, A.S., 2007. Tacrolimus ointment is effective for psoriasis on the face and intertriginous areas in pediatric patients. Pediatric dermatology, 24(1), pp.76-80.
  18. Accordino, R.E., Engler, D., Ginsburg, I.H. and Koo, J., 2008. Morgellons disease?. Dermatologic therapy, 21(1), pp.8-12.
  19. Middelveen, M.J., Fesler, M.C. and Stricker, R.B., 2018. History of Morgellons disease: from delusion to definition. Clinical, cosmetic and investigational dermatology, 11, p.71.

Also Read:

Team PainAssist
Team PainAssist
Written, Edited or Reviewed By: Team PainAssist, Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:February 1, 2021

Recent Posts

Related Posts