Nummular Dermatitis & TNF-Inhibitors

Nummular dermatitis (aka discoid eczema) has an incidence of 2 in 1000 people, mostly men in the age range of 55-65.  However, treatment with a TNF-inhibitor is also a risk factor.

Like many medical terms, the name nummular dermatitis  comes from Latin roots:

  • nummular – from nummus – coin
  • dermis – a layer of skin
  • itis – inflammation

So, nummular dermatitis is coin-shaped inflamed patches of skin.  This rash can itch and burn, even to the extent that it disrupts sleep.  Some people, however, are fortunate enough to skip the unpleasant sensations that typically accompany this unsightly rash (sometimes there are advantages to peripheral neuropathy).

This rash is not contagious.


Nummular dermatitis begins as a group of blisters or tiny red dots.  It quickly becomes a round or oval-shaped patch of red (sometimes pink or brown) skin.  Multiple patches are possible; they can be as small as two millimeters, or as large as four inches.  The rash usually appears on the extremities (arms, legs, feet, hands) or torso.  Thankfully, it is rare for patches to appear on the face.



This rash is unique in appearance and can often be diagnosed based on a visual examination.  Usually no expensive tests are needed, but occasionally the rash will look like ringworm, in which case a doctor might need to take a sample to make an accurate diagnosis.


There are no known causes of nummular dermatitis, however a Dutch study of RA patients done in 2005 showed that 25% of RA patients on TNF-inhibitors needed referral to a dermatologist, vs. 13% of RA patients who had never taken a TNF-inhibitor.  Fortunately, only a small number had nummular dermatitis.  Of note, hepatitic C patients treated with a TNF-inhibitor have an increased risk of nummular dermatitis.  It will be interesting to see the results of follow-up studies now that TNF-inhibitor use is more common in the treatment of RA.


Home treatments aren’t enough to deal with nummular dermatitis. Without adequate treatment, this rash can stick around indefinitely. Even with medical treatment, the rash can take months to resolve – some sources say it sometimes takes a full year for the rash to go away.

The goal of treatment is to:

  • reduce inflammation
  • repair the skin
  • rehydrate the skin
  • if infected, treat the infection

Credit: reduce inflammation, prescription-strength steroid cream or ointment can be rubbed into the rash two-three times daily.  Unless you are Gumby, if your rash is on your back, you will need assistance with the application.  Oral steroids can be used when topical steroids are ineffective (this also eliminates the need for an assistant).

To increase absorption, the steroid cream/ointment should be applied to wet skin – particularly after a shower or twenty-minute soak.  Following application of the topical medicine, a good moisturizer should be applied to wet skin.  Some people recommend covering the medicated areas (ie with plastic wrap) for an hour to hold in the moisture.  Gently pat yourself dry; do not rub with a towel and remove the steroid cream & moisturizer.

Another treatment option – when topical steroids fail – is light therapy (UVB).

Although home treatments alone can’t cure nummular dermatitis, there are a few things you can do.  Take good care of your skin and be sure to moisturize it well.  Also, avoid potential flare-triggers.

A few of the things that sometimes cause flare-ups of this condition are:

  • frequent use of detergents or harsh soaps
  • hot tub usage
  • extreme temperatures (very hot or very cold)
  • extremes in humidity (or lack thereof)
  • rough wool clothing
  • skin injury (ie cut, burn, or insect bite)
  • some medications  (examples include accutane, neomycin, and TNF-inhibitors)
  • sensitivity or allergy to rubber, nickel, cobalt, formaldehyde, or mercury

This means that if your routine is to take a long, hot shower first thing in the morning before dressing in a nice warm, wool sweater and cozy wool socks, you might need to modify your routine.  Make it a shorter lukewarm shower, apply a good moisturizer to your skin, then dress is loose cotton clothing.  If your workout routine later includes spending twenty minutes in a steam room, followed by half an hour soaking/stretching in a hot tub, followed by an hour in a swimming pool, ten minutes in the dry sauna, and then another hot shower, you’re intentionally doing five of the eight things you need to avoid.

See a doctor for accurate diagnosis and treatment if you suspect nummular dermatitis.

Vocabulary for Reading Medical Literature about Nummular Dermatitis

erythematous – red
papules – bumps
vesicles – very small blisters
pruritic – itchy
xerosis – abnormal dryness


Arthritis Research & Therapy
American Academy of Dermatology
DermNet NZ
British Association of Dermatologists

10 thoughts on “Nummular Dermatitis & TNF-Inhibitors

  1. Thanks for the information Socks. I have been dealing with a strange rash on my hands and scalp since Christmas and have a feeling it is some form of eczema. When I called the Dermotologist there was a 2 month wait to see her so I called a second and a third doc. I also got the 2 month for an appointment response from them. I decided to ride out the rash thinking it would be gone in 2 months so why bother. Well, it is not gone and your post seems to indicate why. Hope your problem clears quickly. Guess I’ll call my family doc and see if she can diagnois and treat it. Sigh, so tired of doctors.

    • For the rash on my skin, the dermatologist prescribes exactly the same thing that my FP had already prescribed (triamcinalone cream). Between those two appointments, my podiatrist prescribed ultravate ointment (since he saw the rash on my feet & legs). Ointment is stronger than cream, so it’s no surprise that the stuff on my legs & feet has responded faster than my arms/hands/torso. For the stuff on my head, the dermatologist prescribed a pour-on steroid solution called clobetasol. Good luck, and let me know how it goes.

      • Finally broke down and went to my PCC today. Diagnosis, dyshidrotic eczema. Treatment steroid cream. While speaking with my doctor we tried to come up with some trigger for the eczema. Your post makes me think it may just be that the Enbrel has made me more susceptible. Whatever the cause I am glad to be treating it. Thanks for the information Socks. Also glad to hear the creams are working for you.

  2. I’m on Enbrel and have a developed round patches of reddened, itchy, scaly skin on my feet and ankles. I didn’t connect them with some scalp itchiness until I read this. I have an appointment with my rheumatologist in two weeks and then with a dermatologist two days later. I’m dreading what I’ll be told. I’m just finally getting back to a functioning life again. I don’t want to change medications.

    • 😦 I’m sorry.
      I honestly don’t see any reason to switch biologics over this, since the topical steroids are finally helping. BUT I haven’t talked to my rheumy about it yet, and her opinion might be different. I’m using cream in the morning like a body lotion (because the “apply sparingly” approach wasn’t working), and ointment at night (then putting socks/gloves on to keep it from getting all over my sheets). The clobetasol is twice a day, too. I still have a few small spots, but at the pool I’m no longer given strange looks and asked what happened. Your primary physician might be able to prescribe a topical steroid for you if you don’t want to wait until you see your rheumy. Good luck!

      I’d love to hear what your doctors say. Please let me know.

  3. my dermatologist whom I have been seeing regularly for checkups and who is treating me for skin cancers believes that my “rash” is nummular-dermatitis. Along with moisturizing, gentle soaps and detergents, extra rinses, I am applying Desoximetasone cream once or twice a day. This has greatly relieved the itching, however, I wouldn’t say anything but the itching is under control. I have many more lesions on my legs and I believe some have developed on my hands, arms, and shoulder.
    This is the only blog that I’ve found. If you know of any others, I would appreciate learning about other sources of research and experience.
    Appreciate the camaraderie.

    • Hi Meg! I’m sorry you’re having to deal with this, on top of cancer 😦 The thing that seems to have helped me even better than the dermatologist’s expensive creams & lotions is oil: plain cooking oil from the kitchen. If my skin is broken (I’ve been scratching excessively) I rub it on my skin at the end of my shower then rinse briefly. When the skin isn’t broken, I mix the oil with some salt and use it as a moisturizing exfoliant (scrub with it, then gently rinse). It’s necessary to pat/blot skin dry instead of rubbing with a towel. If I then do my hair and brush my teeth before dressing, the oil has soaked into my skin and I don’t end up with goop all over my clothes. Supposedly prednisone is supposed to help if none of the topical steroids are effective, but I have hesitations about going back on pred. Let me know if the oil works for you, or if you find something else effective.

      • Thanks….I’ll try the oil. It will be a little while before I see my dermatologist again….will let you know what I learn, if anything, then, or before.
        Happy New Year

    • Note: I think desoximetasone (Topicort) is a topical steroid stronger than triamcinalone. The strongest topical would be clobetasol, so there are topical options before going to oral prednisone. (but I am not a doctor, so take that for what it’s worth)

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s