Ostraceous Psoriasis : Causes, Symptoms, Treatment, Diagnosis

Psoriasis is a skin condition in which the skin cells grow and multiply faster than they are shed by the body. This leads to excess cell build-up on the skin leading to plaques or lesions. This plaque build-up is also known as plaque psoriasis. The plaques can be of different colors on different parts of the body.

Ostraceous psoriasis is a rare subtype of plaque psoriasis.⁽¹⁾ In it, the plaques formed are thick and sometimes resemble oyster shells. It is linked with hyperkeratosis, in which the outer layer of the skin hardens. As the outer layer of the skin is made of keratin, if hyperkeratosis occurs the keratin in the outer layer grows unchecked and thickens.

Ostraceous psoriasis is linked with psoriatic arthritis, which is inflammatory arthritis affecting 1 in 4 people with psoriasis.⁽¹⁾ If a person is suffering from both conditions, additional treatments may be needed.

Just like any other psoriasis, ostraceous psoriasis is a result of the overreaction of the immune system increasing cell turnover. The excess skin cells build up on the surrounding surface of the skin leading to the formation of plaques and scales and also chronic inflammation.

The immune system can be triggered by a combination of genetic and environmental risk factors. The factors that trigger psoriasis include:

• Obesity
• Infections such as HIV or the streptococcal infection
• Smoking
• Skin injuries
• Medication that may be used in the treatment of malaria and heart disease

The plaques present on the skin in ostraceous psoriasis are thick and hard.

According to a case report of 2015, these plaques were noted to be concave, surrounded by a ring of thick skin, and covered with scales that remain attached to plaques.⁽²⁾

The plaques present in this condition are present symmetrically on the torso, knees, scalp, elbows, and buttocks.

In plaque psoriasis, the nails are also affected making them pitted or discolored. They may also separate from the nail beds.

If a person develops psoriatic arthritis along, there may be stiffness and swelling in the joints and the symptoms may be worse in the morning.

Ostraceous psoriasis is diagnosed with the help of a physical examination. The symptoms and their duration are enquired about. Medical history is taken about any illness in the past or if recently experienced. Family history is also asked about.

A biopsy may be performed to look for skin cells.

In the diagnostic process, the other skin conditions are ruled out. Sometimes psoriasis is mistaken for other inflammatory skin diseases, such as eczema. In ostraceous psoriasis the severity of plaque distinguishes it.

The focus of the treatment is to reduce the severity of skin lesions and prevent it from flaring and spreading.

The treatment is similar to most types of psoriasis. According to a study, effective treatment involves taking an immunosuppressant drug and topical product that might contain a steroid or an emollient.^{(1, 3)}

A person with ostraceous psoriasis is also recommended:

• Phototherapy
• Oral medications
• Biological drugs
• Medicated creams and ointments and other topical products

According to the American Association of Dermatology Association, over-the-counter remedies such as coal tar and hydrocortisone can be helpful only in mild cases of ostraceous psoriasis.⁽⁴⁾

Additionally, certain strategies are recommended to ease symptoms and reduce the likelihood of psoriasis flares. These include:

• Moisturizing after shower
• Taking shorter showers and using warm water for showers
• Quitting smoking
• Finding ways to reduce stress, such as yoga, breathing techniques, and meditating
• Taking an anti-inflammatory diet

Research shows balancing bacteria and microbes in the diet may play a role in psoriasis and it is, therefore, recommended by dermatologists for taking probiotic supplements.⁽⁵⁾

Ostraceous psoriasis is an autoimmune condition and self-care strategies can be helpful in reducing the symptom from flaring up. People with psoriasis also have an increased risk of cardiovascular disease therefore there is a need for yearly monitoring of cholesterol and electrocardiogram.