When your patient won't stop itching

By Naveed Saleh, MD, MS | Medically reviewed by Kristen Fuller, MD
Published September 30, 2022

Key Takeaways

  • Chronic itch lasts 6 or more weeks. It can be either a symptom or a precursor of disease and seriously impairs quality of life in countless people. About half of people don’t know why they itch, and physicians often ignore the complaint.

  • Antihistamines often fail as treatment for itch. Although newer treatments, such as biologics, are available, cost and adverse effects may detract from their use.

  • Physicians should consider referring patients with intractable itch to “itch” specialists or specialty centers.

Pruritus (itch) can severely sap quality of life. It can also further complicate the lives of people with chronic illness, and could impact mortality.

Chronic itch can either be a symptom of disease or a precursor of serious illness.

Unfortunately, antihistamines often do little to soothe its symptoms. Knowledge of its potential causes may help clinicians determine how to best treat patients with chronic itch.

Understanding chronic itch

Chronic itch refers to itch that lasts 6 or more weeks. The etiology and frequency of chronic itch vary based on age, comorbidities, climate, presence of atopy, and access to healthcare. Other potential contributing factors include living conditions, migration, and rituals. The prevalence of itch varies widely.

Itch accounts for about 1% of total US office visits per year.

Despite pruritus being common, there are scant data on its duration and severity, or on its frequency in patients desiring medical treatment.

Despite the presence of guidelines, experts cite research that suggests about 50% of patients don’t understand why they itch. No strong associations between pruritus and age, sex, geography, or socioeconomic status have been established.

Men and women differ in what they think is most pressing regarding itch, as well as itch location, quality, and scratching behaviors. Moreover, chronic pruritus tends to affect Blacks and Asian/Pacific Islanders more than other ethnic groups.

Chronic itch interferes with sleep and mediates mood disturbance/depression. For instance, itch is considered one of the most distressing symptoms of psoriasis, with more than 75% of patients experiencing it. In patients on hemodialysis, those who experienced itch exhibited a 15% increase in death rates compared with patients who did not; this could be due to sleep issues.

Results of a survey of US dermatologists published in Itch indicated that 4.8% of patients struggled with pruritus.[] This estimate may be on the low side, considering that 67.9% of dermatologists excluded chronic itch secondary to psoriasis, and 44,8% excluded chronic itch secondary to atopic dermatitis.

“There is a lack of awareness, depending on, for example, the MD's specialty; other symptoms may be rated higher and/or itch is ignored,” wrote the authors of an article published in Frontiers in Medicine.[] “This is also caused by a lack of knowledge on itch.”

Chronic itch causes

Etiologies of chronic itch include dermatologic, infections, neuropathic, system, and psychiatric factors. The following are specific causes cited in the Frontiers in Medicine article:

  • Malignant or systemic disease

  • Xerosis cutis (ie, dry skin)

  • End-stage renal disease (ie, patients on hemodialysis)

  • Atopic dermatitis

  • Chronic urticaria

  • Psoriasis

  • Drug interactions (eg, opioids, antineoplastic drugs, antimalarials)

  • Infections (eg, HIV/AIDS)

Psychogenic itch is often proposed as a diagnosis.

This particular diagnosis, however, must be approached gingerly, according to the authors of an article published in Translational Psychiatry.[]

Various aspects of psychogenic itch are contentious, including physiopathology, psychopathology, and classification. The differential diagnosis of psychogenic itch is challenging. Looking forward, brain imaging may help better elucidate psychogenic itch.

"Psychogenic itch is a diagnosis that is (too) frequently proposed by physicians, but patients diagnosed with psychogenic itch are (too) rarely referred to psychiatrists."

Misery, et al.

Treating chronic itch

According to survey data published in Itch, 77.5% of dermatologists prescribed antihistamines as first-line therapy for severe itch, while 76.1% prescribed corticosteroids. Overall, 36.3% of patients did not get relief with available therapeutic options.

Histamine-independent pathways could contribute to chronic pruritus, which explains why antihistamines are ineffective in many patients. In these cases, biologics or κ-opioid receptor (KOR) agonists may help. These drugs, however, are expensive and require pre-authorization if approved.

Adverse effects are another issue with newer antipruritic treatments.

KOR agonists can impact the central nervous system. JAK inhibitors are immunomodulators that are also indicated for itch, but they may cause adverse effects such as infection.

Other options to treat itch include antidepressants, antibiotics, cyclosporine, herbal medicines, antineuralgics, botulinum toxin type A, acupuncture therapy, and phototherapy.[]

It’s extremely important to understand the underlying trigger associated with the itch and try to treat this underlying trigger, rather than “treating the itch.” The itch is most likely a symptom of an underlying disorder, and it may be wise to consult dermatology if the itch does not resolve or improve.

Drug-induced itch

In cases of drug-induced itch, as well as other adverse events secondary to targeted anticancer agents like epidermal growth factor receptor inhibitors, dosage reduction can interfere with the efficacy of treatment. Consequently, decreases in dosages (or flat-out discontinuation) is inadvisable.

Specialists do reduce dosages when patients complain about disturbance in quality of life. Instead of decreasing drug dosages, antipruritic therapies are necessary, according to the authors of an article published in Current Problems in Dermatology.[]

“The medical care of patients with chronic pruritus may be challenging in terms of the diagnosis and therapy of the underlying diseases,” wrote the authors of the review published in Itch.

"To minimize this challenge, dermatologists may need to employ an interdisciplinary approach with specific antipruritic therapy and the collaboration of an itch specialist or center."

Sedlack, et al.

What this means for you

Itch is a pervasive—but often overlooked—complaint among patients. Physicians can follow-up with patients about itch as necessary. Because treating itch can be challenging, cases of recalcitrant itch may be referred to itch specialists or specialty centers.

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