Many people with psoriasis try different diets, such as cutting back on red meat and processed foods or following a gluten-free or a Mediterranean diet. Another important factor is whether you’re taking a biologic medication for psoriasis.

Biologics are a treatment option for moderate to severe psoriasis. These medications can improve skin symptoms and slow down psoriasis disease activity. However, biologics increase your risk of foodborne illnesses because they weaken your immune system.

Because biologics suppress the immune system, they’re often referred to as immunosuppressives. For this reason, they can raise the risk of infections, including food poisoning. If you’re on or starting a biologic to manage your psoriasis symptoms, here are some foods you should consider avoiding to reduce your risk of illness.

1. Unpasteurized Dairy Products

Raw or unpasteurized milk poses a significant health risk for anyone, especially for people on biologics. The pasteurization process (heating milk to a specific temperature) is crucial for eliminating harmful bacteria in dairy products from cows, goats, or sheep. Always check food labels for the word “pasteurized” to ensure the product is safe to consume. Avoid buying milk products, including cheese and ice cream, from farmers markets or stands where you cannot guarantee their safety.

Because biologics suppress the immune system, they may lead to a higher risk of infection, including food poisoning.

2. Mold-Ripened Soft Cheeses

Soft cheeses that are ripened with mold are generally safe for most people to consume. However, biologics for psoriasis can increase your risk of infection from cheeses such as:

• Blue cheese
• Brie
• Camembert
• Feta
• Goat cheese
• Queso fresco

Hard cheeses made from pasteurized dairy are a safer option. If you notice mold starting to grow on a block of cheese, you can cut about 1 inch around the moldy spot. However, if you’d prefer to avoid any risk, it’s best to throw out the cheese. Buying smaller amounts can help ensure you eat all the cheese before any mold develops.

3. Undercooked Red Meat, Poultry, or Seafood

Undercooked meat and seafood can pose serious health risks. People with a compromised immune system from biologics must be cautious to ensure that animal products are cooked to the proper temperature. Cooking foods like meat and seafood to the right temperature kills any organisms that could cause an infection.

Undercooked meat or seafood can harbor dangerous bacteria and parasites, even from high-end restaurants. The risk increases when the food is not prepared correctly. When cooking at home, using a food thermometer is the best way to ensure your food is safe to eat.

Clams, oysters, and mussels should be cooked until the shells open from the heat. For other seafood, like shrimp, scallops, crab, or lobster, heat well until the flesh becomes opaque.

4. Raw Eggs

Raw eggs may carry salmonella bacteria, so it is important to cook and handle them carefully. Avoid runny yolks or over-easy eggs. Instead, choose scrambled or fried eggs that are fully cooked, and eat them while they’re hot.

When cooking at home, using a food thermometer is the best way to know if your food is safe to eat.

Watch out for other foods that may contain raw eggs as an ingredient, such as certain salad dressings, homemade mayonnaise, or raw cookie dough. If you’re unsure about a menu item at a restaurant, ask your server for details on how it’s prepared.

5. Leftover Rice

The safest time to eat rice is right after you’ve finished cooking it. If cooked rice has been sitting for 24 hours or more, you’ll need to thoroughly reheat it before eating. This is because uncooked rice may contain spores of a bacteria called Bacillus cereus, which can survive even after rice is cooked. When cooked rice is left out at room temperature, the spores can grow into bacteria that multiply. The toxins produced by these spores may lead to diarrhea and vomiting, especially in people with a compromised immune system.

To prevent the risk of food poisoning from leftover rice, consider cooking rice in small batches or using steam-in-the-bag rice that’s individually portioned and quick to prepare.

6. Fresh Sprouts

Sprouts contain beneficial antioxidants and fiber, but unfortunately, they can also harbor harmful bacteria such as E. coli and salmonella. The shape and texture of sprouts make them difficult to clean, allowing bacteria to grow and hide. If you’re on biologics, it may be best to avoid raw sprouts, such as alfalfa sprouts. Cook your sprouts thoroughly before eating to kill any harmful bacteria.

7. Well Water

Most home well water systems go through an extensive filtration system, but it’s always best to be on the safe side when taking biologics. If you’re traveling to another country or visiting a rural area, make sure the water is safe to drink. When in doubt, choose purified, bottled water or water from municipal sources. The same rules apply to ice, so you might want to skip the ice if you’re not sure whether it was made with properly filtered water.

Additional Food Safety Tips

Following general food safety tips, such as washing your hands before cooking and storing food at safe temperatures, can help you avoid infections while taking biologics. When in doubt, seek out medical advice from your dermatologist or other healthcare provider.

Not all biologics are the same. Your personal guidelines may vary, especially if you have allergies or other risk factors. Overall, no food is completely off-limits, but it’s important to understand the risks associated with different food groups and how to take precautions. For extra help creating a healthy, individualized healthy diet, ask your dermatology provider for a referral to a registered dietitian nutritionist.

Talk With Others Who Understand

On MyPsoriasisTeam, people share their experiences with psoriasis, get advice, and find support from others who understand.

What foods do you avoid while taking biologics for the treatment of psoriasis? Let others know in the comments below.