In this episode, Larry Green, MD, describes the essential know-hows in diagnosing and treating nail psoriasis, including the importance of recognizing nail psoriasis as a hallmark of psoriatic arthritis.
Dr Green is the section editor of The Dermatologist’s Psoriasis Center of Excellence, clinical professor of dermatology at George Washington University School of Medicine in Washington, DC, and on the National Psoriasis Foundation Medical Board.
Welcome everybody. My name is Dr Larry Green. I'm section editor of the Psoriasis Center of Excellence for The Dermatologist and I’m also clinical professor of dermatology at George Washington University School of Medicine in Washington, DC.
Today we’re going to do a short podcast discussing how to diagnosis and treat nail psoriasis. Yes, it’s a short podcast, but that’s because nail psoriasis is a very shortened area with not that much to say but a lot to say.
So, how do we diagnose nail psoriasis? Well, nail psoriasis usually consists of pitting, nail plate thickening and crumbling, leukonychia, grooves and ridges, oil spots, sometimes red spots, onycholysis, subungual hyperkeratosis, and splinter hemorrhages. That’s a lot of things, but basically, the bottom line is you have nail dystrophy. It’s important in psoriasis, but especially in psoriatic arthritis because that is a hallmark of psoriatic arthritis. One of the criteria for diagnosis of psoriatic arthritis is having nail disease, specifically nail dystrophy like we just talked about.
So severe psoriasis patients, and even mild and moderate psoriasis patients to a less extent, can have nail psoriasis, but it is a hallmark of psoriatic arthritis. So, in the back of your mind, when you see someone who has psoriasis and significant nail disease, it’s very important to think about psoriatic arthritis. So, remember that nail dystrophy in someone who has psoriasis, think of psoriatic arthritis.
Nail matrix psoriasis—that’s the pitting, nail plate thickening and crumbling, leukonychia, the ridging, and red spots in the lunula, which is at the base of the nail plate. Nail matrix disease is oil spots, distal onycholysis, and splinter hemorrhages, those little splinter red-purple streaks you see in the nail. And that’s what we look for in nail psoriasis.
So, when it comes to treating nail psoriasis, it’s, in a way, very difficult to treat just the nails. We don’t have medications that penetrate through the nail dystrophy into the nail matrix, where the nail is manufactured, to affect the nail plate growth. There’s been all sorts of things and medications that have been tried for penetration enhancers, but we just don’t really have it at this point yet.
Topical corticosteroids could be used, especially around the nail matrix, but again penetration is difficult. Calcipotriene can be used; I have not found much success with that, but at least one study I know shown that this was as potent as topical steroid.
Tazarotene is well known to fix epidermal hyperkeratosis and thickening, and it also could theoretically do that in the nail as well, especially pitting in the nail or onycholysis in the nail. Although, that could be irritating, so oftentimes you want to use a topical steroid to reduce irritation with tazarotene, which brings me to a medication, Duobrii, that does not have an indication for treating nail psoriasis. However, when you think about that it has a tazarotene and a topical steroid mixed together, it may be ideal for treating nails because it combines the two together in, some instances, a once-a-day product. Again, when you use a tazarotene product though, whether its by itself or even with a topical steroid, you have to be careful and limit it just to putting it around the nail and nail matrix itself.
So those are topical medications that can be used, but success is usually limited. I would try using these several months, because nails grow out slowly. Remember fingernails especially take about 6 to 8 months to grow and toenails 6 to 9 months to grow out, so when you apply it around the nail matrix, it’s important to give it time.
Because with topical therapies the medium takes some time, some dermatologists, including myself, will use injections of Kenalog, or steroids, into the nail. This is usually done in a low-strength, 2.5 mg per CC is what I usually start with, maybe 3 mg per CC. You put it right along the nail matrix. It is painful. The patient using a lidocaine cream for 30, 45 minutes before can help decrease some of that patient discomfort. I’ve found that Kenalog injections are helpful, much more so than topical treatment. You have to worry about not overdosing because you can cause atrophy of the nail matrix, which would create a new problem. Rather than just having the nail dystrophy, you’d have atrophy of the nail matrix and the middle plate.
Besides topical and intralesional therapy, of course we have oral and biologic therapies. Those work much better to treat nails, but it’s very difficult to say to someone who primarily has nail disease that I’m going to give you an oral or biologic medication just for that if their psoriasis is limited on the body. Now if they have psoriatic arthritis, that’s a different story, because those patients often need systemic therapy, oral or biologic. With limited skin disease, it’s hard to justify that. However, if someone really has severe nail psoriasis—I, myself, and I know many other dermatologists, we’ll use oral therapy or biologic to treat someone’s nails because there’s nothing else that can help. It’s worth it to someone who has that dystrophic nails to clear up their nails. What’s interesting about both oral small molecule and biologic therapy is that they work fairly quickly, more quickly than topical therapy and even intralesional therapy. Even though the nail takes time to grow, for some reason the nail plate starts to normalize, and we see the nail start growing out fairly quickly. I know for example apremilast is an oral small molecule therapy that has shown efficacy in the nails. If you look at a subanalysis of their phase 3 data, efficacy was shown in the nails and fairly quickly.
Biologic therapy also—pretty much all the biologics have shown that they also improve nails, whether it is the subanalysis of the phase 3 data or, you know, something like secukinumab, for example, has their own nail study that showed improvement in the nails.
So, and again, it happens. I’ve seen this in clinical trials that I’ve done myself, that the nails improve when you start the biologic in a matter of weeks, much quicker than the nail grows out. Patients note improving the nails with oral and systemic therapies is much quick than topical therapy.
So, certainly, we need more research on finding better ways to treat nail psoriasis, because unless someone has severe disease, it’s hard to justify using systemic therapy to treat just nails. I hope in the future we have ways to penetrate into the nail matrix with topical or even intralesional therapy that’s safer than intralesional corticosteroids, that will penetrate into the nail matrix and help the nail grow much more normally. Whether this has to be repeated or can do it for a long period would be something for future research.
I think that’s the lacking area in therapy for the nails, is that while we can treat really bad nails with oral small molecule or biologic therapy, it’s just not justified unless the nail disease is severe. I’m hoping that in the future we have topical therapy that can get into that nail matrix, help the nail grow out normally, and control the nail disease in these patients who have less severe skin disease.
Thank you for listening, and please don’t forget to submit feedback comments in the box below.
This is Larry Green, thanks a lot.