How to assess and relieve that perplexing rashless itch
Your patient’s pruritus absent skin lesions might be self-limiting—or indicate systemic disease. Probing the nature of the symptom can point to targeted treatment.
PRACTICE RECOMMENDATIONS
› Undertake a diagnostic work-up for systemic causes of pruritus in patients who have a chronic, generalized itch and abnormal findings on physical examination. C
› Prescribe gabapentin for its effectiveness in treating pruritus caused by uremic and neurologic itch. B
› Consider prescribing one of the bile-acid sequestrants in patients with cholestatic pruritus because these agents can provide moderate relief of the symptom. B
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
When a patient complains of severe pruritus at first presentation, consider pharmacotherapy in conjunction with nonpharmacotherapeutic options. Several of the more effective topical therapies for pruritusa are listed in TABLE 4.20 Well-known systemic agents for this purpose are reviewed below and listed in TABLE 5.7
Systemic treatment
Antihistamines. A staple in the treatment of pruritus for many years, antihistamines are not effective for all causes; however, they are effective in treating paraneoplastic pruritus.20 First-generation antihistamines, with their sedating effect, can be useful for patients who experience generalized pruritus at night.20
Anticonvulsants. Gabapentin and pregabalin are analogs of the neurotransmitter gamma-aminobutyric acid.20 This drug class is helpful in neuropathic pruritus specifically caused by impingements, such as brachioradial pruritus and notalgia paresthetica.20 In addition, of all systemic therapies used to treat uremic pruritus, gabapentin has, in clinical trials, most consistently been found effective for uremic pruritus.6 (Note: Use renal dosing of gabapentin in patients with renal failure.)
Antidepressants. Selective serotonin reuptake inhibitors (SSRIs; eg, fluvoxamine, paroxetine, and sertraline) might cause itch to subside by increasing the serotonin level, which, in turn, works to decrease inflammatory substances that cause itch.7 SSRIs have been used to treat patients with psychogenic pruritus, cholestatic pruritus, and paraneoplastic pruritus.7
Tricyclic antidepressants (eg, amitriptyline and doxepin) lessen the itch by antagonizing histamine receptors and through anticholinergic mechanisms. Tricyclics are best used in the treatment of psychogenic and nocturnal itch.7
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