Keeping an eye on food could help with psoriasis

Q: I'm 27 years old and have itchy skin my doctor says is psoriasis. It's not all the time - it comes and goes. Sometimes it's bad, and other times it's not that noticeable. I've heard that what you eat matters. Can my diet help prevent or control the condition?

A: Psoriasis is a chronic skin condition associated with a malfunction of the immune system. It is marked by the overproduction of skin cells, which results in raised areas of dry, reddened and flaking skin. These areas of inflammation, which are sometimes topped by silvery scales, most often appear on the elbows, knees and scalp. However, they can occur anywhere on the body. Additional symptoms can include burning, soreness and itching; nails that grow thicker than normal or develop pits or ridges; and stiffness or swelling in the joints. Susceptibility to psoriasis, which occurs in both women and men, is inherited. The condition is much more common in adults than in children.

The reasons why the immune system goes a bit haywire aren't yet fully understood. However, flares are associated with triggers such as physical or emotional stress, cold weather, the use of tobacco products and skin injuries. And you are correct that some studies have found diet may also play a role.

Research suggests avoiding inflammatory foods may help ease some psoriasis symptoms and lessen the frequency of flares. Chief among the culprits is sugar, which has long been linked to inflammation. In a mouse study published last year in the Journal of Investigative Dermatology, researchers were able to trigger inflammatory changes in the skin in just a few weeks on a high-sugar diet. Other foods that have been linked to inflammation include alcohol, red meat, saturated fats and the highly refined carbohydrates found in snack foods and ultra-processed foods.

What you do eat can be just as important. Some studies have found that the so-called Mediterranean diet, with its focus on fish, seafood and olive oil, as well as a wide range of fresh vegetables, fruit and leafy greens, may also improve symptoms. These fish-forward diets are rich in n-3 polyunsaturated fatty acids, which are also known as omega-3 fatty acids. These types of fats appear to have an influence on something known as eicosanoids, which are molecules that play a role in causing inflammation. With an increase of omega-3 fatty acids in the diet, researchers suspect that inflammatory processes may be suppressed.

Diet alone has not been found to either control or cure psoriasis, so it's important that you follow the treatment plan outlined by your doctor. And when it comes to food, the responses to dietary changes in people living with psoriasis are highly individual. Some patients have found that a vegetarian diet can lessen the severity of their condition. Others have reported an increased sensitivity to gluten. Pay attention to what you eat, and note whether or not it appears to consistently correspond to changes in your level of inflammation. You may uncover some personal dietary triggers that can help you in managing your condition.

Q: My daughter got a rash across her cheeks that we thought was an allergy. A year later, she was diagnosed with lupus. She's only 17, and the doctors keep putting her on different meds, which worries her dad and me. I've been reading that ginger can be helpful. What do you think?

A: Lupus is what is known as a chronic autoimmune disease. That means it's a long-term condition in which the immune system, which isn't behaving properly, has begun to attack the body's own tissues. There are several forms of the disease, but the most common is systemic lupus, which can affect the joints, skin and certain internal organs, including the heart and kidneys.

Although anyone can develop the disease, about 90% of people with a form of lupus are female. It usually appears between the ages of 15 and 44, which are a woman's reproductive years. Genetics plays a part, and people who have a family member with lupus, or another kind of autoimmune disease, are at higher risk of developing it. It's also more common in people of African American, Native American, Asian, Latino and Hispanic descent.

The rash you noticed on your daughter's face is one of the classic signs of a flare, or episode, of systemic lupus. Known as a butterfly rash, it looks somewhat like a localized sunburn that affects the upper cheeks and spreads across the bridge of the nose. Additional symptoms can include fatigue; swelling, pain or stiffness in the joints; chest pain; dry eyes; and other types of rashes.

Treatment consists of managing symptoms, which, as you have discovered, can require a number of medications. They address issues such as blood clots, inflammation, immune system response, fluid retention, infections and high blood pressure. Each case of lupus is different, with different levels of severity and varying symptoms. As a result, a shifting range of medications can be required. This can be daunting, and even alarming, and we encourage you to discuss your concerns with your daughter's rheumatologist.

As to your question about ginger, there's an interesting new study led by researchers from the University of Michigan. When they looked into the effects of 6-gingerol, the main bioactive compound in ginger, they found evidence it inhibited a specific mechanism associated with abnormal clot formation. Mice that were given 6-gingerol had lower levels of sticky, weblike proteins known as neutrophil extracellular traps, or NETs. These play an important role in immune function. In autoimmune diseases, however, NETs become overactive. After giving the mice 6-gingerol, the researchers noted that the formation of blood clots was markedly reduced.

While this research is exciting, and even encouraging, it's only an early step in a long process. More research is needed in animal models, and then, if that continues to be promising, with humans. In the meantime, your daughter should continue to make regular visits to her rheumatologist and use the medications prescribed. Her doctors will monitor her disease and recommend the treatment protocols that her specific type of lupus requires.

• Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu.