This occurs because the overactive immune system speeds up skin cell growth. Normal skin cells completely grow and shed (fall off) in a month. With psoriasis, skin cells do this in only three or four days. Instead of shedding, the skin cells pile up on the surface of the skin. Some people report that psoriasis plaques itch, burn and sting. Plaques and scales may appear on any part of the body, although they are commonly found on the elbows, knees, and scalp.
Types of psoriasis
Nail psoriasis. Psoriasis can affect fingernails and toenails, causing pitting, abnormal nail growth and discoloration. Psoriatic nails might loosen and separate from the nail bed (onycholysis). Severe cases may cause the nail to crumble.
Guttate psoriasis. This type primarily affects young adults and children. It’s usually triggered by a bacterial infection such as strep throat. It’s marked by small, drop-shaped, scaling lesions on the trunk, arms or legs.
Inverse psoriasis. This mainly affects the skin folds of the groin, buttocks and breasts. Inverse psoriasis causes smooth patches of red skin that worsen with friction and sweating. Fungal infections may trigger this type of psoriasis.
Pustular psoriasis. This rare form of psoriasis causes clearly defined pus-filled lesions that occur in widespread patches (generalized pustular psoriasis) or in smaller areas on the palms of the hands or the soles of the feet.
Erythrodermic psoriasis. The least common type of psoriasis, erythrodermic psoriasis can cover your entire body with a red, peeling rash that can itch or burn intensely.
Psoriatic arthritis. Psoriatic arthritis causes swollen, painful joints that are typical of arthritis. Sometimes the joint symptoms are the first or only symptom or sign of psoriasis. And at times only nail changes are seen. Symptoms range from mild to severe, and psoriatic arthritis can affect any joint. It can cause stiffness and progressive joint damage that in the most serious cases may lead to permanent joint damage.
What causes and triggers psoriasis?
Psoriasis triggers vary from person to person. What may worsen your psoriasis might not have any impact on someone else. Common psoriasis triggers include:
Stress is one of the most common psoriasis triggers. At the same time, a psoriasis flare can cause stress. This may seem like an endless loop. However, relaxation techniques and stress management may help prevent stress from impacting psoriasis.
Injury to Skin
Psoriasis can appear in areas of the skin that have been injured or harmed. This is a result of the Koebner [KEB-ner] phenomenon, which states scratches, sunburns, bug bites and vaccinations can all trigger a psoriasis flare.
Heavy alcohol use can trigger psoriasis flare-ups. If you excessively use alcohol, psoriasis outbreaks may be more frequent. Reducing alcohol consumption is smart for more than just your skin too. Your doctor can help you form a plan to quit drinking if you need help.
Some medications are considered psoriasis triggers. These medications include:
• antimalarial medications
• high blood pressure medication
Anything that can affect the immune system can trigger psoriasis. That is why you may experience a flare following an ear infection, bronchitis, tonsillitis or a respiratory infection. There is a connection between streptococcus infection (strep throat) and guttate psoriasis, as it often triggers the first onset of guttate psoriasis in children.
It is possible to have strep throat without showing symptoms. If you have had strep throat in the past, talk with your health care provider about getting a strep throat test if your psoriasis flares.
The weather may trigger a flare. Cold weather can often cause psoriasis flares due to less sunlight and humidity, heated and drier indoor air, as well as stress and illness. Warm weather can often improve psoriasis because of natural sunlight and higher humidity.
Other Possible Triggers
Although it is less common, some people with psoriasis suspect that allergies, certain foods, alcohol or environmental factors trigger their psoriasis. A great way to learn about your unique set of triggers is to track them over time. Keeping records of your symptoms and triggers can help you anticipate and treat your flares.
• Psoriatic arthritis, which causes pain, stiffness and swelling in and around the joints
• Eye conditions, such as conjunctivitis, blepharitis and uveitis
• Type 2 diabetes
• High blood pressure
• Cardiovascular disease
• Other autoimmune diseases, such as celiac disease, sclerosis and the inflammatory bowel disease called Crohn’s disease
• Mental health conditions, such as low self-esteem and depression
When to see a doctor
• Becomes severe or widespread
• Causes you discomfort and pain
• Causes you concern about the appearance of your skin
• Leads to joint problems, such as pain, swelling or inability to perform daily tasks
• Doesn’t improve with treatment