Some of the drugs used to treat MS can cause side effects that involve the skin. Learn what to look for and how to respond.

By Cathy CassataMedically Reviewed by Jason Paul Chua, MD, PhD

Reviewed: June 5, 2023

Various medications for multiple sclerosis (MS) can have a variety of effects on your skin. While some side effects can be prevented with over-the-counter or home remedies, others may indicate a serious drug reaction that should be reported to a medical professional.

Of course, if you’re not sure whether what you’re experiencing is a drug side effect or whether it’s considered “serious,” speak to your doctor or pharmacist. And if drug side effects are preventing you from using prescribed MS medications, let your healthcare team know. There may be alternatives to the drug you’re using or ways to reduce the side effects.

Injectable MS Medications: Pain and Redness

Injectable medications for MS can cause pain at the injection site, as well as skin redness and firm welts in the area. For example, injection-related reactions such as redness, swelling, itching, and pain are a common side effect of the disease-modifying therapy (DMT) ofatumumab (Kesimpta).

According to Jacqueline A. Nicholas, MD, a neurologist at OhioHealth Multiple Sclerosis Center in Columbus, Ohio, the following techniques can help prevent or reduce these reactions:

Pretreat with ice or heat. Before injecting, Dr. Nicholas recommends applying ice to the skin to make the area cold or a heating pad to make it warm. The change in temperature seems to reduce the pain from the injection.

Take a shower first. Nicholas tells her patients to take their injections right after showering. “When the skin is wet, it’s more porous, and many patients find it easier to inject then,” she says.

Apply a witch hazel pad. After an injection, Nicholas suggests applying a witch hazel pad (often used for hemorrhoid relief) to the injection site. This helps to narrow the blood vessels in the skin, preventing the body’s release of histamine, a chemical that can cause pain and itchiness, Nicholas explains.

Talk to your doctor if you experience skin-related reactions after taking injectable medications for MS.

Oral Medications: Flushing and Rash

One oral DMT, dimethyl fumarate (Tecfidera), can cause flushing, or a feeling of warmth accompanied by redness.

“Women often describe this feeling as being like a hot flash they would normally only experience during menopause,” says Nicholas. “They feel hot, and their skin looks red on their face and chest. It can tingle and even itch, and it typically lasts 10 to 15 minutes, but that can decrease over time while on treatment.”

She notes that taking an aspirin before taking the medication can reduce the flushing, or in some cases prevent it completely. According to the prescribing information for Tecfidera, aspirin without enteric coating should be taken 30 minutes before taking Tecfidera. (Enteric coating is sometimes called “safety coating.”)

Diroximel fumarate (Vumerity) is another oral DMT that commonly causes flushing, redness, itching, or rash.

According to the website for Vumerity, taking the drug with food (avoid high-fat, high-calorie meals or snacks) may help reduce flushing. Ask your doctor if taking aspirin before taking Vumerity may also reduce flushing.

Stop taking Vumerity and seek emergency medical assistance immediately if you experience an allergic reaction (such as welts, hives, swelling of the face, lips, mouth, or tongue, or difficulty breathing).

IV Infusions for MS: Rash, Hives, and ITP

MS drugs that are delivered intravenously have the potential to cause allergic reactions, resulting in a rash. This rarely occurs with the DMT natalizumab (Tysabri), but it occurs more commonly with a drug called rituximab (Rituxan), which is not specifically approved for MS but is sometimes used to treat the disease.

To reduce redness and hives from such reactions, the antihistamine diphenhydramine (Benadryl) or steroids are given. Nicholas says slowing down the infusion can also help.

Tysabri Normally, Tysabri is given over the course of an hour in a medical facility, after which you must remain at the facility for an additional hour for observation, so that any serious allergic reactions can be treated promptly.

The requirement to stay for observation may be lifted after a certain number of infusions with no allergic reaction. However, allergic reactions can occur more than two hours after the start of an infusion and can occur for the first time after a dozen uneventful infusions.

Lemtrada Another infused DMT, alemtuzumab (Lemtrada), can cause a rash that commonly appears as red patches on the chest and arms and may be itchy.

“There is also a risk of an autoimmune attack against the platelets, called ITP, which could appear as a petechial rash,” says Nicholas.

Signs of ITP, or immune thrombocytopenia, include small red, pink, or purple spots on the skin (petechiae); easy bruising; or bleeding that takes a long time to stop. You should report any of these signs promptly to a healthcare professional.

Ocrevus Infusion reactions such as itchy skin, rash, hives, and flushing are also a common side effect of the DMT ocrelizumab (Ocrevus), according to the drug’s website.

Some of these reactions can be serious, so tell your healthcare provider if you develop any of these symptoms.

According to the dosing and administration guide for Ocrevus, taking 100 milligrams of intravenous methylprednisolone (or a similar corticosteroid) about 30 minutes before your Ocrevus infusion may reduce the frequency and severity of infusion reactions. Taking an antihistamine about 30 to 60 minutes before your infusion may further reduce the frequency and severity of infusion reactions.

Hair Loss and Thinning

Hair loss and thinning have also been reported as side effects of various MS drugs. According to a study published in May 2021 in Neurology: Neuroimmunology and Neuroinflammation, hair loss and thinning were the most common skin-related side effects among patients taking the oral DMT cladribine (Mavenclad).

According to Mayo Clinic, hair loss and thinning have also been reported among MS patients with multiple sclerosis taking immunosuppressive agents such as azathioprine.

Hair loss and thinning have also been observed among patients taking the oral DMT teriflunomide (Aubagio), but the hair loss is typically mild and temporary, according to an evaluation published in Neurology and Therapy in December 2018. Less commonly, hair loss has also been reported in patients taking beta-interferons, which are injected.

Rise in Herpes Infection Risk

A number of MS drugs can increase your risk of developing herpes zoster (shingles), a viral infection that can cause a painful rash. These include the oral DMTs diroximel fumarate (Vumerity), ponesimod (Ponvory), and cladribine (Mavenclad) as well as the infusion DMT Ocrevus.

The CDC recommends Shingrix, a non-live vaccine for the prevention of herpes zoster (shingles) and related complications, for adults 50 years and older and people who are age 19 or older and are taking certain MS medications, according to the National Multiple Sclerosis Society (NMSS).

Possible Rise in Skin Cancer Risk

Lemtrada has also been associated with rare cases of skin cancer, per the drug’s website.

Fingolimod (Gilenya), an oral DMT, has also been linked to skin cancers including basal cell carcinoma, squamous cell carcinoma, melanoma, and Merkel cell carcinoma, according to the drug’s website.

Skin cancers have also occurred with drugs in the same class as Ponesimod (Ponvory), according to the drug’s website.

Nicholas recommends that people with MS receive skin screening from a dermatologist to look for suspicious moles before they begin treatment with Lemtrada and other MS drugs associated with skin cancer, and that they get rescreened every year while they’re taking them.

According to the Skin Cancer Foundation, tell your doctor if you have any changes in the appearance of your skin, including:

• A growth that gets bigger and appears pearly, transparent, tan, brown, black, or multicolored
• A mole, birthmark, or brown spot that increases in size, thickness, changes color or texture, or is larger than a pencil eraser
• A spot or sore that persistently itches, hurts, crusts, scabs, or bleeds
• An open sore that does not heal within three weeks

To prevent skin cancer, reduce the amount of time you spend in sunlight and ultraviolet (UV) light. Wear clothing to protect your skin from the sun, and use a broad-spectrum (UVA/UVB) sunscreen with a sun protection factor (SPF) of 15 or higher. When you’re going to be outside for an extended period of time, use a water-resistant, broad-spectrum sunscreen with an SPF of 30 or higher, according to the Skin Cancer Foundation.

MS Drug Side Effects That Affect Your Skin | Everyday Health