Itchy Skin

Welcome to another edition of the Doctor's Note where we talk about what's on our minds when it comes to your health.

This week I sat down again with Dr. Joni Sago to talk about one of the most frustrating symptoms patients bring to our offices: itchy skin. When there is no obvious rash, it can be easy to assume the problem is simply dry skin and reach for another moisturizer. But persistent itching can sometimes point to something happening beneath the surface. The skin is the body’s largest organ, and it can give us important clues about overall health, including possible issues involving the liver, kidneys, minerals, or hormones.

We also talked about why antihistamines do not always solve the problem. Not every itch is driven by histamine, and researchers are learning more about other pathways, including interleukin-31, or IL-31. Dr. Sago explained how newer targeted treatments may offer relief for certain chronic itching conditions. We also discussed several problems that can feel like skin conditions but may actually begin elsewhere in the body, including notalgia paresthetica, which often causes an intense itch in the middle of the back, and brachioradial pruritus, which commonly affects the forearms and may be connected to nerve irritation in the neck. We closed with a closer look at Grover’s disease, why it can be difficult to recognize, and what patients and providers can do to help calm the skin and find relief. The important thing is not to dismiss persistent itching, but to slow down, look closely, and ask what may be causing it.

PODCAST NOTES 

• Itchy skin that presents without any visible rash is often quickly attributed to dryness, but it’s crucial not to overlook more serious underlying systemic causes. Conditions such as liver and kidney disease, low ferritin (even in the absence of anemia), and thyroid dysfunction can all manifest as itchy skin. Regardless of age, but especially in patients over 30 or 40, thorough screening blood work should be performed to ensure these issues are not missed before leaping to topical solutions.

• Ferritin plays a central role in not just red blood cell production but also in thyroid function and skin health. As we discussed, you may not be overtly anemic, but if your ferritin level isn’t at least around 50, you’re not truly at an optimal level—and this can impede thyroid hormone conversion (T4 to T3) and drive persistent itch. The standard laboratory “normal” ferritin range is misleadingly low, so always aim for optimal, not just normal.

• Traditionally, itch has been thought of as strictly mediated by histamine, so many patients—especially older adults—end up taking antihistamines like Benadryl with little benefit and potential risks, including anticholinergic side effects. However, most chronic itch isn’t actually histamine-driven, meaning antihistamines may be unhelpful or even harmful for many patients dealing with persistent itch.

• The discovery of interleukin-31 (IL-31) as a central molecule in the itch pathway has dramatically changed how we think about and approach chronic itching. IL-31 is the main messenger responsible for sending itch signals from the skin to the brain. Excitingly, new biologic medications like nemolizumab that block IL-31 are emerging and have yielded life-changing results in patients with severe, unexplained itch—though presently, they are only approved for certain skin conditions like eczema and prurigo nodularis.

• For individuals who experience intense, localized itching—such as the classic unreachable spot on the middle of the back—what may seem like a mysterious skin issue is frequently due to nerve entrapment from neck arthritis or poor cervical spine posture. This condition, known as notalgia paresthetica, is best addressed by targeted physical therapy to strengthen the neck’s extensor muscles, rather than creams or steroids which are ineffective since the source is neurological, not dermatological.

• Similar to notalgia paresthetica, brachioradial pruritus (persistent forearm itch) or meralgia paresthetica (numb/itchy spot on the outer thigh) arise from nerve compression near the spine or pelvis. These itch syndromes make it clear that not all skin symptoms originate in the skin itself—sometimes the real culprit is musculoskeletal nerve impingement. Recognizing these patterns allows for effective treatment, such as physical therapy and ergonomic adjustments, instead of endless topical or systemic medications.

• Grover’s disease is a highly underrecognized and misdiagnosed cause of severe itching, particularly on the trunk, often dismissed as folliculitis or eczema. Upon very close inspection, the “bumps” are erosive and reflect a breakdown in the cellular “glue” holding the epidermis together, often with no significant inflammation present. It reminds us that careful visual examination and barrier repair—rather than just inflammation suppression—are vital to addressing the true problem.

• Treatments for Grover’s disease can include topical vitamin A and D analogs, such as calcipotriene, or in specific cases, oral agents like acetretin (a vitamin A derivative) and even celecoxib, which modulates calcium flux in skin cells. Often, over-the-counter topical ointments containing vitamins A and D can be a good first step for those seeking a supplement-based approach—complex and costly compounding isn't always required. Importantly, each of these approaches targets the core disruption in skin cell adhesion and turnover, offering much-needed relief for this stubborn affliction.

Persistent itching deserves a closer look—both at your skin and at your overall health. Don’t settle for being told to simply use more moisturizer when the problem continues. Whether there is a visible rash or not, your provider should be willing to consider metabolic, neurologic, and dermatologic causes.

Sometimes the answer is found in a place you would not expect, from your cervical spine and posture to your iron stores, thyroid function, or vitamin D level. My biggest encouragement is to stay curious, ask questions, and keep looking until you understand what your body may be trying to tell you. As Dr. Sago reminded us, sometimes finding the answer means taking the time to look two inches closer.

Stay educated. Stay healthy.

Till next week.