What is the best course of treatment for a 16-year-old female with a history of itching all over her body?

Management of Generalized Pruritus in a 16-Year-Old Female

Start immediately with liberal application of high lipid-content emollients combined with self-care advice (avoiding hot water, irritants, and triggers), then perform a focused diagnostic workup to identify any underlying systemic cause before escalating to pharmacologic therapy. 1, 2

Initial Assessment and Diagnostic Workup

Clinical Evaluation

• Perform a thorough skin examination of all body surfaces, including finger webs, anogenital region, nails, scalp, palms, and soles to distinguish primary dermatologic disease from pruritus without visible skin lesions 3, 4
• Obtain detailed history focusing on: onset and duration of symptoms, timing patterns (worse at night suggests certain etiologies), medication review (including over-the-counter and herbal remedies), travel history, and potential triggers 5, 3
• Assess for constitutional symptoms (fever, weight loss, night sweats) that may suggest malignancy or systemic disease 5, 3

Laboratory Investigation

The British Association of Dermatologists recommends the following core screening tests for generalized pruritus without obvious dermatologic cause 5, 2:

• Complete blood count with differential (to evaluate for hematologic disorders, eosinophilia, or malignancy) 2, 4
• Comprehensive metabolic panel including liver function tests (to assess for hepatic causes) 5, 2
• Urea and electrolytes (to evaluate renal function) 5, 2
• Ferritin and iron studies (iron deficiency can cause pruritus) 5
• Fasting glucose or HbA1c (to screen for diabetes) 3, 4
• Thyroid function tests only if additional clinical features suggest endocrinopathy 5, 2

Additional testing should be guided by clinical findings and may include HIV/hepatitis serology if risk factors present, chest X-ray if constitutional symptoms exist, or erythrocyte sedimentation rate 5, 3, 4

Treatment Algorithm

First-Line Therapy (Start Immediately)

Emollients and self-care measures form the foundation of treatment for all patients with generalized pruritus, regardless of underlying cause. 1, 2

• Apply high lipid-content emollients liberally and frequently to maintain skin hydration and restore skin barrier 1, 2
• Implement self-care advice: avoid hot water, harsh soaps, irritants, and known triggers 1, 2
• Limit water exposure and bathing time 4

Second-Line Topical Therapy (If Emollients Insufficient)

If emollients alone do not provide adequate relief after initial trial 5, 1:

• Topical clobetasone butyrate or menthol preparations may be beneficial 5, 1
• Topical doxepin can be prescribed with strict limitations: maximum 8 days duration, 10% body surface area maximum, 12g daily maximum 5, 1
• Hydrocortisone 2.5% applied to affected areas 3-4 times daily for inflammatory causes 6, 7

Avoid crotamiton cream (Strength B recommendation against), topical capsaicin, and calamine lotion as they are ineffective. 5, 1

Third-Line Systemic Therapy (If Topical Therapy Fails)

Non-sedating H1 antihistamines are preferred as second-line systemic therapy. 5, 1

• Fexofenadine 180 mg daily or loratadine 10 mg daily 5, 1
• Consider combining H1 and H2 antagonists (e.g., fexofenadine plus cimetidine) for enhanced effect 5, 1
• Cetirizine 10 mg daily (mildly sedative) may be used if non-sedating agents fail 5

Critical caveat: Avoid sedative antihistamines (like hydroxyzine) except in short-term or palliative settings due to dementia risk, particularly concerning in younger patients who may use long-term. 1, 2

Fourth-Line Therapy (Refractory Cases)

If antihistamines are insufficient, consider 5, 2:

• Paroxetine, fluvoxamine, or mirtazapine (SSRIs/antidepressants with antipruritic properties) 5, 2
• Gabapentin or pregabalin (for neuropathic component) 5, 2
• Naltrexone (opioid antagonist) 5, 2

Cause-Specific Considerations

If Drug-Induced Pruritus Suspected

• Perform medication cessation trial if risk-benefit analysis acceptable 5, 2
• For opioid-induced pruritus (if cessation impossible): naltrexone is first-choice (Strength B recommendation) 5, 2

If Hepatic Pruritus Identified

• Rifampicin is first-line treatment (Strength A recommendation) 1, 2
• Cholestyramine as second-line, sertraline as third-line 5, 2
• Do not use gabapentin in hepatic pruritus 5, 2

If Iron Deficiency Found

• Iron replacement therapy is indicated 5, 2

If Neuropathic Component Suspected

• Consider topical neuropathic agents (menthol, pramoxine, lidocaine) alone or combined with topical steroids 7
• Gabapentin or antidepressants (sertraline, doxepin) may be effective 7
• Skin biopsy may confirm small fiber neuropathy if suspected 5, 2

When to Refer

Refer to dermatology if: 5, 1

• Diagnostic uncertainty exists
• Primary care management does not relieve symptoms after appropriate trials
• Systemic therapy beyond antihistamines is being considered
• Patient requires phototherapy or advanced immunomodulatory treatments

Critical Pitfalls to Avoid

• Do not perform exhaustive malignancy workups routinely—investigations should be guided by thorough history, physical examination, and screening labs 3
• Do not delay treatment while awaiting workup results—begin emollients and self-care immediately 3
• Do not use long-term sedative antihistamines except in palliative care settings 1, 2
• Do not overlook medication review—drug-induced pruritus is common and reversible 5, 3
• Do not assume psychogenic etiology until thorough evaluation for organic causes is complete 5, 4