A three-person panel covered the topic of itch recently at The Dermatology Education Foundation’s DEF Essential Resource Meeting 2024 (DERM2024) NP/PA CME Conference in Las Vegas, Nevada, with David Cohen, MD, MPH, leading “How to Avoid Doctor Strange: Pearls for Monitoring and Managing Itch.” Dr. Cohen was joined by Wendy Cantrell, DNP, CRNP, and Kara Gooding, MMS, PA-C. Following is a transcription of their discussion, edited with participant approval for clarity and length.

Dr. David Cohen: An itchy patient coming to the office might be very obvious and very easy. However, if no clear rash is present, it can be one of the most vexing and concerning patients that ever walk into the office, short of someone coming in denuded from TEN or a bad blistering disease. Itch has a terrible impact on patients’ quality of life. At-risk populations such as the elderly and darker-skinned patients present variably. Grover’s disease patients have 400 little red dots on their trunk and barely know they’re there or that it’s itchy, but then you have some with eight dots and the itching is driving them crazy. The severity of the skin disease does not always dictate the predictability of itch.

We will talk about blood tests such as complete blood count (CBC) with differential other tests that you might do. The most important thing is that if a patient has an itch of unknown origin, with no clear eczema or itchy dermatosis, and they have been itching for fewer than 12 months, you really need to initiate a workup to figure out what’s going on because their skin probably isn’t the primary problem causing it. You can be the true hero in this situation when you discover an early malignancy or an early systemic disease. When you see eosinophilia, of course, you need to think of allergic phenomena, drug eruptions, fungal diseases, or parasites in the gastrointestinal tract.

What are your most concerning issues, and what kind of blood tests are you performing? 

Kara Gooding: Like you said, when patients come in with itch without a primary rash, I tell them this is one of the most difficult things that we encounter in our practice. For baseline screening, we start with some simple tests, but we may eventually need to dive into some deeper tests. I always call it the alphabet soup: We start with a CBC, a CMP, a TSH, and a UA, and sometimes I’ll add an ANA and a chest X-ray. For elderly patients, who very frequently have itch without a rash, I sometimes immediately order BP180 and BO230 tests to check for nonbullous pemphigoid. Besides that, making sure they are up to date on their screenings, mammograms, colonoscopies, and primary care visits is important.

Wendy Cantrell: Biopsy is hard in this kind of condition because it may not give us the information that we need. If I decide to biopsy a patient like this, I tell them it may not give us much information. They can’t become frustrated with the process. Even no information is good information to have. And sometimes it does give us what we need. Sometimes it gives us a cutaneous T-cell lymphoma (CTCL) diagnosis. So, I don’t biopsy everyone, but I do it frequently, especially with recalcitrant patients. 

DC: This discussion can go two different ways. The itchy eczema patient, the unusual itchy psoriasis patient, and the lichen planus patient with drug eruption make you feel comfortable when they’re complaining of itch because it’s part of the disease process. The itchy patients who are out of proportion to what you suspect are different. But we’re going to cross the lines between the two throughout this discussion.

Pruritus is incredibly common. It’s not a disease; it’s a symptom. I tell patients who do not have an obvious dermatosis: “Your body is trying to tell us something and I am trying to speak its language, so we’re going to do this workup. The reason I’m doing a chest X-ray is to see if anything is going on in your lungs or if there are any enlarged lymph nodes.”

Itching is common. It impacts quality of life, mood, and psychosocial conditions, such as anxiety and depression. With age, some of the obvious things like dry skin neuropathies and even psychological issues will have an impact. Itch in pregnant patients is more of an emergent thing; if they’re starting to get itchy, you need to act on that quickly. Even if you see some excoriations, you cannot give triamcinolone to those patients. They need to go back to the OBGYN and get a full workup for cholestasis. We will go into that in further detail.

It is valuable to use an itch assessment tool and document the results. We do it with every patient who might have an itchy dermatosis. With any inflammatory disease, we ask a patient to rate their itch on a scale of zero to 10, with 10 being the worst itch you might imagine and zero being no itch. Of course, some patients directly give you a number and some patients give you a 5-minute story without ever using a numeral. But it is important to ask those patients to provide a number for where they are now. The next question, then, is on the same scale: What is the worst itch you felt in the last 24 hours, from zero to 10? They might say, “Well, last week it was at 11.” Eleven was not a choice, and the question was last night. But corralling everyone into this is the fun part. The process is incredibly valuable. It’s a documented, effective, and reliable tool and it will give you good information. Do you use this tool, and if so, how frequently?

WC: We do it with every dermatitis patient. This is now part of MIPS (Medicare’s Merit-based Incentive Payment System), so itch is critical to our success in documentation. My medical assistants do it for me. I often discuss the itch assessment tool with the patient as well, so MIPS is not the only reason for doing it, but MIPS is a big part of our reimbursement strategy. 

KG: We actually have it on an intake form, so patients complete it even before they see my medical assistant, and then my medical assistants ask them again. I love it as an assessment tool when you can look back at a patient’s chart during their follow-up visit and say, “Your score last time was an eight and now you’re a two.” They might say they don’t feel much better, but their assessment says the itch is significantly better. They may not remember that, but that’s what we talked about the last time, 

DC: Never discuss the last itch score that they gave you until you get the new itch score, because they will anchor it. It’s classically unreliable in younger children. Kids who have had lifelong eczema give very low numerical rating scores for itch. I just saw a patient who was 6 or 7, and she was covered in eczema, but she gave me itch scores of three and four. She looks like she’s a nine, but that’s all she knows. How does she know anything but itching? Also, when you cross diseases, it’s not very reliable. In clinical trials for eczema, itch scores on moderate to severe disease are generally between seven and eight. But the itch scores in psoriasis trials are between six and seven. There is no way that a moderate-to-severe psoriasis patient is one point away from a moderate-to-severe eczema patient. That severe eczema patient doesn’t sit still in your office and the psoriasis patient is looking pretty good. If someone gives you an eight, nine, or 10, they are grabbing you by your white coat and shaking you to do something. You don’t take an eight, nine, or 10 and just say, “We’ll do these blood tests and see it in a couple of weeks.” You need to initiate something and address the itch with them. 

Again, you can use the variable itch scores. I like the numeric rating scale (NRS). There are visual analog scales for which people can point to very unhappy faces and very happy faces. Get the history down. How long has this been going on? Is there any history? Ask about all the atopic diseases and any other diseases that may be of consequence. Of course, if you are suspicious and if there’s no rash, ask about fever, night sweats, chills, and weight loss. If you practice for long enough, you will pick up Hodgkin’s disease in patients in their 20s who present to you with itching. You will find patients in their 50s, 60s, and 70s with myelodysplastic syndrome or polycythemia with aquagenic urticaria. You just need to listen for it and not look at secondary scratches. But I like seeing some of these things because I know I can explain their itch. These are a little bit more tolerable, but there’s a lot here to unpack. You use the Hanifin criteria as effectively as possible. You use medical history and family history to guide you. I had a patient with a very itchy forehead patch. She had a rash. Someone thought she had contact dermatitis, but she could not sleep; she had an NRS of three and a 24-hour worst NRS of eight. I patch tested her, and she had a number of issues, so I decided to start her on dupilumab. Now, she’s reporting a 95% improvement, yet her NRS scores went to one and five to six. That’s the impact that a three-point change in itch score meant to her because she can sleep; before, she couldn’t sleep. Documenting this note is so easy and it passes all of my reviews by external sources.

WC: You’re right that you cannot rule out malignancy. I recognized what was eventually diagnosed as non-Hodgkin’s lymphoma in a patient who was approximately 20 years old. He was having such terrible itch and could not get relief with basic care. Those are the types of things in your career that you never forget, because of the potential consequences if you had missed it. CTCL is another—perhaps a patient is in the early patch stage and just beginning to have itch. Those are two things I have seen that are always in the back of my mind when somebody comes in and just saying, “I am just dying of itch.”

KG: The malignancy concern is huge. Some impactful cases in my career turned out to be Paget’s disease of bone after the patients had itchy eczematous patches on their breasts. I have a very low threshold for biopsy. I may treat for two weeks, but they absolutely must come back in, and if it’s not better, we need a biopsy. It’s almost always associated with underlying invasive breast cancer, so you don’t want to miss that. The other possibility that is worth mentioning again is looking for that nonbullous pemphigoid in elderly patients; sometimes it’s a needle in a haystack, but if you can catch it early, you can really help those patients. Oftentimes, the delay in that diagnosis can be many, many years, and that can also be associated with underlying malignancies. 

DC: Those patients could look like they have urticaria, not spongiotic dermatitis, and they’ll also describe a pin prick sensation. Sometimes it’s like their epidermis tearing away from their dermis. Yet, it is often misdiagnosed.

Itch is very complex; it cannot be simplified to IL13, IL31, or some Janus kinase pathway. It’s really complicated. Brains involve the nerves. Many cellular pathways and cytokines cause itch, and so there’s no unifying way to deal with it.

Systemic cause of itch can include renal disease. You will pick up things on your comprehensive metabolic panel. Look at the estimated glomerular filtration rate (eGFR) and the blood urea nitrogen/creatinine ratio; once that starts creeping up, people get itchy. Hyperparathyroidism, which is secondary to some kidney disease, is a possibility. Look for cholestasis. A patient’s bilirubins may be normal, but if you still suspect liver disease, you can get bile salts. Diabetic dermopathies can be itchy; they’re almost neuropathic. Dermatomyositis can be incredibly itchy on the scalp and in other areas; patients may have shawl signs, holster signs, Gottron papules, and heliotropes that look like eczema. They get sent in for contact dermatitis workups all the time. You just need to step back and say, what’s the quality of that red plaque? Take a look at the cuticles. I’m sometimes afraid to get an antinuclear antibody (ANA) test, but I do it anyway.

I do want to highlight drug-induced symptoms. Every day, patients come in with itch that is challenging to diagnose. Therein lies this quest, this journey into drug related reactions. I implore people to go through the drug list and look at the times that patients started medicines. Those will be the easy ones—times when they change doses. But the tricky ones are the statins. A patient may be on statins for 10 or 15 years. They may have had a dosage adjustment or a viral infection and, suddenly, they’re getting pins and needles and they’re getting itchy. Nobody ever implicates the statins. You stop the statins for 2 to 3 weeks and nothing happens because you need 3 to 4 months of being off the statin. Most patients can come off statins for 3 to 4 months. They haven’t been on statins for 50 or 60 years of their life, so a couple of months is not a problem. If they really need something, they can go on a PCSK9 inhibitor to cover them. We are writing the letters of medical necessity for that. Selective serotonin reuptake inhibitors (SSRIs) for depression and anxiety also can cause itching, and while that takes years to come on, it takes months to go away. The same goes for proton pump inhibitors. 

When you’re expanding blood tests, consider high-end deficiencies such as vitamin D or vitamin B deficiencies. I add on, out of pure neurosis, serum protein electrophoresis (SPEPs), immunofixation, and occasionally urine protein electrophoresis (UPEP) testing in the younger patient, or the older patient with recent onset itch and absolutely no rash. That’s where I can find certain things. 

Neuropathic itching is another challenge. We all see notalgia paresthetica so frequently—that hyperpigmented patch just off-center in the middle of the back. It is more common in women than in men. You explain that it is not a primary dermatologic issue. While topicals help, they’re not perfect. You do need to deploy systemic therapies if it gets really bad, but that’s not very common.

Many people miss brachial radial pruritus—that strip of itching, prurigo nodules or excoriations just on the anterolateral part of the arms, bilateral or unilateral. You can’t look at those cases with a magnifying glass. You need to take a step back, look from where you’re taking your notes, and see what the distribution is. Those patients are most successfully treated with physical therapy or sometimes with gabapentin or pregabalin. Don’t underestimate the decompression there.

KC: I saw two cases in which brachial radial pruritus went away after the patients had carpal tunnel surgery.

DC: Wow. So, it was feedback from distally. I don’t know if I’ve seen that. Regardless, those cases are tough and it’s very hard to find neurologists willing to acknowledge the problem. Unless the nerve is crushed or there’s discogenic disease that’s crushing the dorsal roots, it’s hard to get neurologists to get on board. When you find a neurologist who buys in to that, they’re golden to you. 

Disclaimer: This content was developed independently and is not endorsed by the DEF or DERM2024.

David E. Cohen, MD, MPH

• Charles C. and Dorothea E. Harris Professor and Executive Vice Chairman for Operations and Strategy, The Ronald O. Perelman Department of Dermatology, New York University Grossman School of Medicine.

Wendy Cantrell, DNP, CRNP

• Certified Nurse Practitioner, Forefront Dermatology, Mountain Brook, Alabama.

Kara Gooding, MMS, PA-C

• Board-Certified Physician Assistant, Center for Dermatology & Plastic Surgery, Sun Lakes, Arizona.