Itch is an unpleasant sensation that drives the urge to scratch and is the most common symptom experienced by people with eczema. Itch can significantly impair one’s quality of life by disturbing sleep, school and work performances, social functioning, and psychological well-being.
What Causes Itch in People with Eczema?
There are numerous triggers for itch in people with eczema. Some common itch triggers in eczema are temperature changes, humidity, dry weather, sweat, emotional stress, certain fabrics, and soaps. Even the sound and sight of scratching can trigger itch. People with eczema have a defect in the skin’s natural protective barrier. In a sense, the skin becomes “leaky.” As a result of this leaky skin, water evaporates more quickly out of the skin surface which causes skin dryness, leading to skin inflammation and itching. Leaky skin also allows itch-inducing chemicals (pruritogens) to enter the skin more easily. When the inflammation becomes chronic, our skin actually becomes more sensitive to itch and the urge to scratch becomes even worse. This leads to a vicious “itch-and-scratch cycle.”
What Are Some Ways to Fight Itch in Eczema?
Treatment for itch in eczema ranges from topical medications and behavioral therapy to more complicated systemic medications. Frequently, a combination of approaches may be needed to achieve good control.
Topical Anti-Inflammatory Medications: Topical Steroids and Calcineurin Inhibitors
Topical steroids are the first-line treatment for itch in people with eczema. They work by decreasing skin inflammation and the release of itch-inducing molecules in the skin. Because long-term use of topical steroids can lead to thinning skin and stretch marks, topical calcineurin inhibitors may be used instead on areas with thin skin (such as the face, neck, armpits, and groin) and when anti-inflammatory medication is needed for a longer period of time. Both medications work by decreasing the level of inflammatory molecules that trigger itch in our skin; therefore, they can improve both itch and eczema.[3,4]
Medications That Affect the Nerves: Neuromodulators
Medications that change the metabolism and release of certain chemicals (such as serotonin) in our nervous system can help to reduce itching. Some of these medications belong to a group of medications known as mood-stabilizers, anti-anxiety, and anti-depressants. For example, doxepin is a sedating medication in the family of medications known as tricyclics but also works like a very potent anti-histamine. Similar to other sedating antihistamines such as diphenhydramine and hydroxyzine, oral doxepin helps to reduce itch by causing drowsiness and helps people with eczema get better sleep at night. Doxepin cream can be used in conjunction with topical steroids to help reduce itch in people with eczema, but may cause skin allergies in some people.
Treatment with oral selective serotonin re-uptake inhibitors such as paroxetine and fluvoxamine can significantly reduce itch. The selective serotonin re-uptake inhibitors can improve skin lesions in a number of conditions associated with chronic itch but may be especially beneficial in people with eczema.
Systemic Anti-Inflammatory Medications
When eczema is moderate to severe and unresponsive to topical anti-inflammatory medications, systemic anti-inflammatory medications that suppress the immune function may be needed to help decrease itch and severity of skin symptoms. These medications are usually used along with topical anti-inflammatory medications in order to take a more intensified effect on eczema. Some of these medications include systemic steroids, mycophenolate mofetil, cyclosporine, methotrexate, and azathioprine.
Anti-histamines are some of the most commonly prescribed medications for itch. There are two main classes of oral anti-histamines: sedating and nonsedating. Antihistamines are believed to have itch-relieving properties because they prevent histamines (an itch-inducing chemical) from being released by our immune cells. Sedating antihistamines cause drowsiness and therefore may help to lessen nighttime scratching to prevent further skin damage. However, there is relatively little data to support their anti-itch effect. In fact, the guidelines of care for eczema from the American Academy of Dermatology states that there is insufficient evidence that sedating or nonsedating antihistamines are effective in relieving itch or hive symptoms associated with eczema. However, sedating anti-histamines do help people get better nights of sleep, which can lower stress and indirectly help with itch.
Light Treatment: Phototherapy
Phototherapy is also known as light therapy. The idea of treating eczema with phototherapy came from the observation that people with eczema had improved symptoms in the summer months when sunlight exposure was greater. Ultraviolet light type B or ultraviolet light type A can be used to treat itch in eczema. Narrow band ultraviolet light type B (narrowband UVB) is a type of phototherapy where the light source emits a narrow range of wavelengths, between 311 to 312 nanometers, to allow shorter exposure time but higher light intensity, which means people will need less ultraviolet exposure to achieve a treatment response. Phototherapy can decrease the number of nerve fibers in the skin to decrease itch sensations and restore the balance between anti-inflammatory and inflammatory molecules in the skin. In a randomized controlled study, researchers found that after 24 sessions of phototherapy, 90% of the people with eczema who received narrowband ultraviolet light type B experienced improvement in their itch, whereas 63% reported an improvement in their itch with ultraviolet light type A treatments, and 52% reported improvement in their itch after receiving visible light. Narrowband ultraviolet light type B appears to be the most effective phototherapy for people with eczema.
Other Topical Anti-Itch Medications
Menthol, pramoxine, and capsaicin are compounds that act like local numbing medications to temporarily block the transmission of itch signals from the skin to the central nervous system. Menthol causes a cooling or “minty” sensation when applied topically, which also helps itch by activating cold-sensing receptors to soothe the skin. Pramoxine belongs to the class of drugs called local anesthetics and works by numbing the skin to block pain and itch sensations. Capsaicin is a compound derived from chili powder and widely used as a topical pain and anti-itch treatment. However, in a systemic review, research has concluded that there is currently no convincing evidence that capsaicin is useful in treating itch. Topical anti-itch medications such as menthol, pramoxine, and capsaicin should be carefully selected under the guidance of your practitioner because they have the potential to cause irritation, skin allergy, and may worsen eczema.[14,18]
Acupuncture and Acupressure
Acupuncture and acupressure have been shown to significantly reduce allergen-induced itch intensity. Acupuncture may be more effective than cetirizine (an anti-histamine medication) if it is performed during episodes of itch. In people with moderate to severe eczema, acupressure using a small titanium bead to massage an acupoint on the arm 3 times weekly can significantly improve itching. Despite encouraging results, additional clinical studies with larger sample sizes and more repeatable approaches are needed to verify the benefit of acupressure and acupuncture in treating itch in eczema.
Hypnotherapy is also known as hypnosis and comes from the Greek word hypno, meaning “sleep." It is an exercise where the therapist brings one to deep relaxation and an altered state of consciousness, or trance, in order to help a person gain more control over his/her bodily function and psychological responses. Hypnotherapy can help people with eczema to gain more control over undesired behaviors such as scratching and help them to better cope with anxiety and skin discomfort. It can also help to control itch and promote mind-body connection to encourage relaxation and healing. There are a number of cases reported where children and adults with eczema have improvement in their skin severity and itching that were previously unresponsive to conventional treatments.[22,23]
Biofeedback is a technique to help one gain more control over normally involuntary functions, such as scratching. Biofeedback of muscle tension can be used to teach eczema patients how to relax, which can decrease skin inflammation and stress-triggered skin conditions like eczema.
Cannabinoids are a class of chemical compounds that act on the cannabinoid receptors in our cells to influence nervous, hormone and immune functions. Cannabinoids can help itch by interrupting how the neuronal messages are transmitted within the itch-sensing pathways. Clinical studies have shown that a cream containing N-palmitoylethanolamine, an endocannabinoid (cannabinoid that is naturally produced in our bodies) can decrease skin inflammation and improve itch by 46% within 6 days in people with eczema. A synthetic cannabinoid called HU210 can reduce histamine-induced itch in healthy people and may be helpful in treating itch symptoms in people with eczema.
Clinical studies have shown that young children who are massaged by their parents for 20 minutes daily for 1 month in addition to getting standard topical steroids and moisturizers experience significant improvement in skin redness, scaling, skin thickness, itching, and scratching, compared to children who only received standard treatment but without massage. Caution should be exercised when choosing a massage oil, as certain essential oils may cause skin allergy and irritation and may worsen itch.
The most effective way to combat itch in eczema requires a treatment that integrates several approaches to address the mind and body interaction, which encompasses antiinflammatory medications, relaxation techniques, skin sensation modulation, and behavioral therapy.