Treatment of Common Constant Itches
Start with liberal emollient application and non-sedating oral antihistamines (fexofenadine 180 mg or loratadine 10 mg daily) as first-line therapy for generalized pruritus of unknown origin, while simultaneously investigating for underlying systemic causes. 1
Initial Management Strategy
Foundation: Skin Barrier Restoration
- Apply emollients liberally and frequently to all affected areas—this is the cornerstone of treatment regardless of underlying cause 1, 2
- High lipid-content moisturizers should be used multiple times daily to maintain skin barrier function 3
- Dry skin itself triggers itch through nerve fiber activation and neuropeptide release, making moisturization therapeutic rather than merely supportive 4
First-Line Systemic Therapy
- Non-sedating antihistamines are the primary oral treatment: 1
- These agents are FDA-approved for itching and should be used during daytime 6, 5
- Important caveat: Most chronic pruritus is non-histaminergic, explaining why antihistamines often have limited effectiveness—do not abandon other therapies if antihistamines fail 3
Topical Adjunctive Treatments
- For localized intense itch: Apply moderate-to-high potency topical corticosteroids 1
- For generalized mild-to-moderate itch: Topical menthol 0.5% preparations provide additional symptomatic relief 1, 2
- Topical doxepin may be prescribed but limit to 8 days, 10% body surface area, and 12 g daily 1
- Avoid: Crotamiton cream, topical capsaicin, and calamine lotion—these lack efficacy 1
Nighttime Management
- First-generation antihistamines may be used only short-term for nighttime pruritus interfering with sleep 1
- Critical warning: Do not use sedating antihistamines long-term due to significant dementia risk with chronic use 3
Second-Line Systemic Therapies (If First-Line Fails After 2 Weeks)
Neuropathic Agents
- Gabapentin 900-3600 mg daily or pregabalin 25-150 mg daily for neuropathic itch pathways 1, 2
- These agents reduce peripheral calcitonin gene-related peptide release and modulate central μ-opioid receptors 1
Combination Antihistamine Therapy
- H1 and H2 antagonists together (e.g., fexofenadine plus cimetidine) may provide enhanced effect 1
Antidepressants
- Selective serotonin reuptake inhibitors: paroxetine or fluvoxamine 1
- Mirtazapine 1
- Doxepin (also a potent histamine antagonist) 1
Opioid Receptor Modulators
Other Agents
Mandatory Diagnostic Workup
Initial Laboratory Evaluation
- Urea and electrolytes to screen for chronic kidney disease 1
- Liver function tests (consider bile acids and antimitochondrial antibodies) 1
- Complete blood count to evaluate for hematological malignancy 2
- Thyroid function testing 2
- Iron studies (both deficiency and overload can cause pruritus) 1
Additional Testing Based on Clinical Context
- Travel history and infectious screening: Consider HIV, hepatitis A/B/C serology, malaria, strongyloidiasis, and schistosomiasis if risk factors present 1
- Medication review: Trial cessation of potentially causative medications if risk-benefit analysis acceptable 1
- Vitamin D level: Supplementation may help some patients with generalized pruritus 1
When to Refer to Secondary Care
- Diagnostic doubt 1
- Symptoms persist despite primary care management 1
- Pruritus lasting beyond 2-4 weeks without clear cause 3
- Development of systemic symptoms suggesting malignancy 1
Alternative and Adjunctive Therapies
Phototherapy
- UVB phototherapy (narrowband or broadband) may benefit various causes of pruritus 1
- Particularly useful in uremic, cholestatic, HIV-associated, and lymphoma-associated pruritus 1
Acupuncture
- Consider acupuncture in combination with Chinese herbal remedies as second-line therapy 1
- Relatively safe with few side-effects, though evidence is limited 1
Behavioral Interventions
- For distressed patients with chronic pruritus, consider psychosocial and behavioral interventions including education, lifestyle modifications, relaxation techniques, cognitive restructuring, and habit reversal training 1
Critical Pitfalls to Avoid
Do Not Assume Histamine-Mediated Itch
- Most chronic pruritus involves non-histaminergic pathways, explaining limited antihistamine effectiveness 3
- Continue other therapies even when antihistamines fail 3
Do Not Skip Emollient Therapy
- Proper skin care with emollients is foundational and should never be omitted even when using systemic agents 3
- Dry skin management directly addresses pathophysiologic mechanisms of itch 4
Do Not Use Sedating Antihistamines Long-Term
Do Not Delay Investigation
- Pruritus persisting beyond 2-4 weeks warrants systematic evaluation for underlying systemic disease 3
- Approximately 20-30% of generalized pruritus cases have significant underlying causes 1
Special Populations
Elderly Patients
- Pruritus in those over 65 years (Willan's itch) is very common and often associated with xerosis 1
- Consider bullous pemphigoid as rare presenting feature—may require skin biopsy and indirect immunofluorescence 1
- Avoid long-term sedating antihistamines due to increased dementia risk 3
Drug-Induced Pruritus
- Opioid-induced: Naltrexone is first-choice if cessation impossible; alternatives include methylnaltrexone, ondansetron, droperidol, mirtazapine, or gabapentin 1
- Chloroquine-induced: Consider prednisolone 10 mg, niacin 50 mg, or combination therapy; dapsone may also relieve itch 1