Milk thistle has been reported to cause skin rashes, such as eczema, hives and pruritus, according to Drugs.com. Although not proven, milk thistle is commonly used to treat toxicity, alcohol-related hepatitis, cancer and diabetes. If you choose to use milk thistle to treat any medical condition, talk with your doctor first. Milk thistle has not been evaluated by the U.S. Food and Drug Administration, or FDA, and should be used with caution. Common skin rashes resulting from milk thistle are a minor allergic reaction in the skin.
Skin rashes from milk thistle are the result of the presence of IgE antibodies that increase histamine levels in the skin, according to the American Academy of Allergy, Asthma and Immunology. After ingesting the herb, you immune system reacts to the substance as if it was dangerous and begins to build a defense against the supplement. The body creates IgE antibodies that attempt to fight off the herb. IgE antibodies cause mast cells in the skin to produce histamine, which causes inflammation and irritation.
Eczema is a chronic skin condition that is mostly found in young children, but can affect adults throughout their life, according to the American Academy of Dermatology. Eczema is a hypersensitivity of the skin that causes blisters to form, typically on the face, behind the legs and arms. The blisters can fill will liquid that can weep and crust over. Eczema also causes leathery, dry and scaly patches to form that can crack, leaving the skin susceptible to secondary infections.
Hives and Pruritus
The exact cause of hives is still undetermined, but the presence of histamine can trigger the rash. Hives are for the most part considered harmless but cause discomfort and itching. This rash develops in various shapes and sizes in clusters of welts that have defined borders, according to MayoClinic.com. Pruritus is the medical term used for itchy skin. You can also experience general itchiness after taking milk thistle.
If you develop a rash after ingesting milk thistle, discontinue use and talk with your doctor. Allergic skin rashes can be treated with over-the-counter hydrocortisone to alleviate the itch and help reduce inflammation, according to the American Academy of Allergy, Asthma and Immunology. In severe cases, your doctor may prescribe corticosteroid creams to calm the skin. Apply a cold compress to the affected areas to reduce the itch.
Other adverse reactions reported by Drugs.com include abdominal pain, bloating, fullness, changes in bowel habits, nausea, diarrhea, headaches and impotence.