Is it psoriasis or ringworm?

Have you notice a skin rash and are wondering if it is psoriasis or ringworm? Continue reading to learn more.

The use of a moisturizer may be the simple solution to skin problems that have your skin looking dry and scaly. Sometimes, the problem may need more than a moisturizer. In any case, you need to know the exact cause of the skin problems to get the appropriate solution.  

Ringworm and psoriasis are two skin conditions that, though different from each other and of different causes, have some close similarities.  

What is ringworm? 

Ringworm is a skin condition caused by a fungus, not a worm. Its name stems from the shape of a single lesion which is rashes appearing as a circle- the shape of a ring. The rash encircles a central clear and flaky dry area. When there are numerous ringworm rashes in a single area, they merge so much that it becomes difficult to decipher the ring in each lesion. This makes it look less like a ring and more like a plaque- a patchy area of skin redness, and dry flakes. 

Ringworms can occur in different parts of the body and are named based on the part of the body where they are observed. Medically called Tinea, ringworm is highly contagious. It can be contracted from animals (pets in the home), from the environment like bathrooms, from contact with an infected person, or from the use of personal belongings of an infected person such as towels and combs.  

Ringworm on the body is called tinea corporis: the rash is reddish or darker than the surrounding skin in people with a dark complexion.   

psoriasis or ringworm
Picture shows difference between psoriasis and ringworm

On the scalp, tinea capitis: It causes hair loss in the areas of the scalp affected. It is more common in children.  

Ringworm on the feet (in between the toes and sole of the feet) tinea cruris or athlete’s foot: appears reddish, painful, and itchy. 

 On the facial skin under beards is called tinea barbae: it may also cause hair loss. 

And on the nails tinea unguium: May cause discoloration and chopping off of the nails.  

What is psoriasis? 

Psoriasis is a skin condition that occurs due to an autoimmune disease in which some cells in your skin are being produced more than necessarily needed. In some cases, psoriasis affects the joints, nails, and eyes as well. A combination of genetics and environmental factors may contribute to this disease. Psoriasis is not caused by an infectious agent and is therefore not contagious.  

Psoriasis is of different types, affecting different parts of the skin with a distinct appearance for each type of psoriasis.  

Types of psoriasis are: 

  1. Plaque psoriasis: This is the most common type of psoriasis and has the most semblance of ringworm. The Area affected is well delineated. It affects the outer elbow, scalp, knee, and trunk. 
  1. Guttate psoriasis: This appears in the back, chest, and abdomen. It is a red, raised, itchy rash occurring a few days after a bacteria infection. 
  1. Nail psoriasis: May appear as nail pitting or discoloration.  
  1. Pustular psoriasis: It affects any part of the body including the palms and soles of the feet. It appears as raised rashes filled with pus.  
  1. Scalp psoriasis: The scalp is dry, and flaky with raised red areas. Only severe cases are associated with hair loss.   
  1. Erythrodermic psoriasis: It is a large area of red peeling scaly skin. 
  1. Inverse psoriasis: It is seen on the flexural surfaces or skin folds such as the armpit, groin, and under the breasts. 
  1. Psoriatic arthritis: Affects the small joints of the hands and feet. It occasionally affects large joints like the knee joint, causing pain and swelling. of those with skin symptoms; usually in the hands and feet and, occasionally, the large joints 
  1. Oral psoriasis: It appears as cracked, crusty corners of the lips which can extend to the surrounding skin.  
Types of psoriasis
Types of psoriasis

How are ringworm and psoriasis similar? 

It is imperative to differentiate between these two diseases for they are similar in the following ways 

  1. they both cause skin rashes that are reddish and raised compared with the surrounding skin 
  1. They both cause itching of the skin. 
  1. They both make the skin look dry and flaky. 
  1. Both may be seen in the arms, legs, trunk, and scalp.  
  1. Treatment modalities are based on the area of the body affected. 

Ringworm or psoriasis- what age group is affected? 

Ringworm of the scalp (tinea capitis) is seen in typically hot, humid climates because the organism that causes it thrives better in humid environments.  

It is more common in children particularly tinea capitis because of their developing immune system. Tinea corporis is most common in the  Preadolescent age group. Psoriasis can occur in any age group but is more common between the ages of 20 to 30 years and between ages 50- 60 years.  

Ringworm versus psoriasis- which gender is more prone? 

Although ringworm occurs in both males and females, it is more common in women of childbearing ages because of close contact with children.  

Psoriasis is more common in women than men but eye symptoms are more common in men.  

Ringworm vs psoriasis- the difference in appearance and other symptoms. 

Ringworm is limited to the skin and its appendages (hair and nails) whereas psoriasis is a systemic disease with skin manifestations. Hence psoriasis may also affect the joints and the eyes. It causes joint pain, stiffness, difficulty with movement, and deformities. In the eyes, it may cause dryness, redness, and itching.  

Psoriasis rashes are seen typically on both sides of the body, for instance, both right and left elbows. On the contrary, ringworm may be seen only on one or both sides of the body.  

Ringworm vs psoriasis Diagnosis 

Clinical history and examination alone may be sufficient to make a diagnosis of ringworm and psoriasis. However, your doctor may want to confirm the diagnosis by taking scrapings of the borders of the rash to have a look under a microscope. This helps confirm ringworm when the fungus is identified under the microscope. 

Skin biopsy is the confirmatory test of choice for psoriasis. 

Ringworm vs psoriasis- treatment? 

Although ringworm infection may go away without treatment, some ringworm may require antifungal medications applied as a cream to the lesions (topical treatment), shampoos, or oral medications. 

Ringworms may be treated with antifungal creams alone or a combination of antifungal creams and oral medications. Complete treatment results in a cure. The appearance of new similar rashes is most likely from reinfection.  

On the contrary, psoriasis is a chronic skin condition that is not cured but can be treated with creams, oral medications, and ultraviolet light therapies. In addition, people with psoriasis are encouraged to avoid triggers that may cause a flare (recurrence or worsening) in the symptoms. Cigarette smoking, alcohol ingestion, skin infections, certain drugs, emotional stress, and skin injuries may trigger flares in Psoriasis.  

While hydrocortisone creams are recommended in the treatment of psoriasis because they help suppress the abnormality of the immune system which caused the disease, using them on ringworms can worsen the infection.  

The use of steroids containing creams in ringworm is counterproductive for it may weaken your skin’s defence and make it easier for the fungus to invade deeper into the skin, causing a more serious infection. It may also cause a bacterial infection in addition to a fungal infection. This is an avoidable complication.  

 Steroid creams do not kill the fungus but may reduce itching and redness. This is because these symptoms are a result of your body trying to fight off the infection, steroids suppress this fight, thereby making it easier for the fungus to occupy a larger area of skin. Steroid creams may even cause a change in the appearance of the rash making it more difficult to diagnose. This is the reason the use of triple-action creams is strongly discouraged as a treatment for ringworm.  

Treatment is based on surface areas of involvement, body site(s) affected, the presence or absence of arthritis, and the thickness of the plaques and scale. 

To conclude, ringworm is a common infection that is curable with medications and does not cause more serious health problems except if it becomes complicated. You should complete treatment for the duration prescribed by your doctor even if it appears that the rashes disappeared before you completed treatment. Psoriasis flares can be prevented by avoiding the triggers and taking prescribed medications. 

About the author

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Grace is an internist currently practising in Nigeria. She has gained experience practising both in the private and public health sectors over the last ten years. She is passionate about giving patients adequate information about their health conditions. She believes that a large part of the management of chronic diseases lies with patients' understanding of their illnesses and the need for lifestyle modifications and medications.