Parapsoriasis is a group of skin conditions that cause scaly rashes on the torso and lower extremities. This condition resembles psoriasis, although parapsoriasis presents differently and has a different response to typical psoriasis treatments.
Treatment of parapsoriasis is based on symptom management. Topical steroid creams and moisturizing lotions are some of the most common treatments. The doctor may also recommend phototherapy sessions. These sessions may take place at the doctor’s office or home using a special UVB lamp. Since the sun’s rays contain ultraviolet light, getting safe sun exposure may also help affected skin.
If the patient does not respond to treatment, the dermatologist may recommend photochemotherapy. In this treatment, the patient either ingests pills or soaks in a solution that makes their skin more sensitive to ultraviolet light. Next, a medical professional exposes the rash to UVA light. The initial treatment is only a minute long, with sessions gradually working up to half an hour.
When the patient has a large amount of skin covered by the rash, he or she stands in a special cabinet that holds at least 24 UVA bulbs that are each six feet long. The patient may only wear undergarments during this treatment to maximize skin exposure. Since longer treatments can get quite warm, the technician may use fans or air conditioning to cool the cabinet.
Smaller rashes may only need spot treatment. The patient soaks the affected area in the special solution, then a medical technician or doctor uses a small lamp to focus treatment on the affected area. This method is usually reserved for hands or feet.
When a parapsoriasis rash does not respond to treatment, skin grafts may be necessary. In this procedure, a surgeon removes healthy skin from another area of the body. Next, he or she removes the affected skin and replaces it with the healthy skin. It can take a few weeks for the patient to return to normal activities. If the graft is in the legs, arms, hands or feet, he or she may need physical therapy to keep scar tissue from hindering movement.
Sometimes lifestyle changes help relieve parapsoriasis symptoms.
- Avoid scratching or rubbing irritated skin. Use moisturizers to keep skin supple and promote healing.
- Cool showers or baths may soothe inflamed skin. However, avoid excessive washing or scrubbing to prevent additional irritation.
- Wear light, comfortable clothes. Cotton is both soft and breathable.
- Stay hydrated. Drinking plenty of water helps keep skin moist.
- Avoid using detergents, soaps, and lotions that contain perfumes or dyes.
Identifying types of parapsoriasis
There are two forms of parapsoriasis. Small plaque parapsoriasis (SPP) is usually benign (non-cancerous). The lesions typically form small, yellowish patches that are less than five centimeters (about two inches) wide. Other names for small-plaque parapsoriasis include Digital Dermatosis or Chronic Superficial Small Plaque Dermatosis.
Large plaque parapsoriasis (LPP) has bigger, irregularly-shaped rashes. Many people who have this type of parapsoriasis develop a type of lymphoma known as mycosis fungoids. This cancer affects white blood cells but begins in the skin. Large-plaque parapsoriasis is also known as Chronic Superficial Large Plaque Dermatosis and Parapsoriasis en Plaques.
Some medical experts consider large-plaque parapsoriasis and small plaque parapsoriasis are separate diseases. Others believe that SSP is an early sign of mycosis fungoids.
Understanding the difference between psoriasis and parapsoriasis
Looking at psoriasis and parapsoriasis, there is no visual difference between the two conditions. Both appear as large, patchy rashes. However, under a microscope, they are very different. Psoriasis shows up on your scalp, knees, elbows, and back. While parapsoriasis can be present in these places too, it can also form on your chest, abdomen, and lower extremities.
Another difference in the two is that psoriasis most commonly affects younger adults. Parapsoriasis is more common in middle-aged males, specifically those aged 30-60.
Uncovering parapsoriasis causes
The exact cause of parapsoriasis is unknown. However, the condition is thought to stem from several different diseases that lead to inflammation of the skin. Certain conditions may trigger parapsoriasis or make it harder to treat. They include
- Bacterial and viral infections
- Depriving skin of sunlight
- Cuts, burns or insect bites
- Dry skin and irritation
- Alcohol or tobacco use
- Drugs such as beta blockers, antipsychotics, and antimalaria medications
Large plaque parapsoriasis and the herpes virus
Although not enough research exists to declare it a cause officially, LPP is associated with the herpes virus. Nearly 90 percent of the skin lesions associated with LLP have human herpes virus 8 (HHV8).
Parapsoriasis risk factors
Risk factors are characteristics that may raise your chances of getting a disease or condition. However, increased risk factors do not mean you will get a condition, just as an absence of certain risk factors does not mean you will not develop a condition.
Parapsoriasis is a rare skin disease typically seen in middle-aged and elderly adults. It is found in both males and females, but most commonly affects middle-aged men. Parapsoriasis can affect people of all races, and ethnic backgrounds.
People who have a weakened immune system may be more at risk of having parapsoriasis. This includes individuals who have Acquired Immune Deficiency Syndrome (AIDS), autoimmune disorders like rheumatoid arthritis, certain cancers, or psoriatic arthritis.
Parapsoriasis is not contagious, and cannot be transmitted from one person to another through close contact, bodily fluids or airborne sources. Some medical professionals believe it may be passed down through families.
Defining the symptoms of parapsoriasis
Parapsoriasis symptoms can manifest quickly or slowly. They may also disappear for a while, then return. The rash is most often pink or red, but it may also appear brown or have a yellowish tinge. The skin is flaky and may appear silvery. Affected areas are often raised and thick.
SSP may form long, thin plaques that look like finger impressions from a slap on the back or a tight hug. One tell-tale sign of LPP is that it may disappear with sun exposure. It is not uncommon for it to disappear during the summer months, then reappear during the winter.
When plaques appear on the face, individuals with parapsoriasis may struggle with having a healthy self-image. Going through several cycles of healed and inflamed skin can also be taxing. Both family and mental health care professionals can provide coping skills and support.
Since most cases of large-plaque parapsoriasis develop mycosis fungoids, it is important to monitor skin changes. Plaques may develop tumors or ulcers. If you experience these symptoms, talk to a doctor.
There are a variety of tests doctors may use to determine whether a patient has parapsoriasis. The first is to look at the patient’s medical history and perform a complete physical examination. Doctors may also use one or more of the following tests.
- Skin biopsy involves taking a sample of the affected skin and examining it under a microscope or conducting tissue studies on it. This test helps rule out conditions that are similar to parapsoriasis.
- Dermoscopy is a test done with a magnifying tool, allowing a dermatologist to take a closer look at the affected skin.
- Wood’s lamp test uses ultraviolet light to help the doctor see changes in skin pigmentation.
If a doctor suspects the patient has mycosis fungoids, he or she may order additional tests. They include bloodwork to check white blood cell counts and genetic testing.
Many conditions have similar signs and symptoms. Your medical provider may order additional tests to rule out other skin conditions. Some of these similar conditions include contact dermatitis from allergies, fungal skin infections, or rashes from drug reactions.
Parapsoriasis prognosis and prevention
Parapsoriasis is a condition many people have all their lives. Some patients have more severe symptoms than others and may require stronger treatment measures. With the proper treatment and lifestyle changes, the symptoms are controllable.