Drug-induced Pruritus

Pruritus means itching, a feeling that makes you want to scratch your skin. Sometimes it comes with a rash, but not always. If the itching lasts for six weeks or more, it’s called chronic pruritus.

In people with cancer, pruritus is more common, especially when taking certain modern cancer treatments known as targeted therapies or immunotherapies. These include:

• EGFR inhibitors (e.g. gefitinib, cetuximab, erlotinib, Osimertinib)
• Monoclonal antibodies (e.g. rituximab, tositumomab)
• Other targeted agents like VEGFR, BRAF, MEK, and mTOR inhibitors
• PD-1/PD-L1 inhibitors (e.g. nivolumab, pembrolizumab)
• CTLA-4 inhibitors (e.g. ipilimumab)

Studies showed that itching affects up to 1 in 7 cancer patients taking these treatments. Most of the cases are mild, but it can be more severe and affect daily life in some patients (about 1-2%).

What Are the Complications of Pruritus?

Itching may seem minor, but when it's severe or persistent, it can cause significant discomfort and affect daily life:

1. Mental and emotional distress: Constant itching can lead to frustration, anxiety, fatigue, and even depression. It may disturb sleep and make everyday tasks harder to manage.
2. Skin damage: Scratching can break the skin, causing infections, bleeding, or thickened patches over time.
3. Social withdrawal: Some people feel embarrassed or uncomfortable in public, which may lead to avoiding social activities or missing work.
4. Other skin changes: Pruritus often appears with other skin symptoms like redness, bumps, or acneiform rashes. Treating these skin changes can help reduce the itching.

How Do Doctors Assess and Manage Pruritus?

Before treating pruritus, your doctor will review your medical history, including recent medications, cancer therapies, and any transfusions. They’ll check when the itching started, if it followed a specific drug, and whether it came with skin changes like rashes or bumps. A physical exam will help spot visible signs, and you may be asked to rate your itch and explain how it affects your daily life. Emotional factors like stress and fatigue are also considered. Since everyone experiences itching differently and there’s no single test for it, your doctor will use this information to guide treatment. If the itch is linked to a rash related to anti-cancer treatment, treating the rash often helps.

A. Skin care and moisturizers

• Apply fragrance-free, alcohol-free creams or ointments twice daily
• Use moisturizers containing 5–10% urea to soothe and hydrate dry skin
• Bathe with gentle, non-soap cleansers
• Take lukewarm showers; avoid hot water to prevent irritation
• Keep nails short to prevent skin damage from scratching

B. Diet and hydration

• Drink plenty of water to maintain skin hydration
• Limit processed and sugary foods, which may worsen inflammation and itching
• Avoid spicy food or alcohol if they trigger or worsen symptoms
• Eat more vitamin-D and zinc rich food to support skin health

C. Clothing and comfort

• Wear loose, breathable clothing made of cotton
• Apply cool compresses to relieve itchy areas
• Use sunscreen (SPF 15 or higher) to protect against sun irritation
• Avoid wool and synthetic fabrics that may irritate the skin
• Minimize exposure to heat, sweating, and other known triggers

D. Relaxation and stress management

• Practice calming techniques such as deep breathing or meditation
• Ensure adequate rest, as stress and fatigue can intensify itching

Topical creams or ointments

• Use gentle skin care with regular moisturizers
• If your skin is dry, moisturizers containing urea or polidocanol can help soothe it
• For mild to moderate itching, consider creams with menthol (0.5%) or steroid creams such as mometasone, betamethasone, or low-dose hydrocortisone (1%)

Oral medications

• Antihistamines can help relieve itching:
  • Non-sedating second generation antihistamine like loratadine (10 mg daily) are suitable for daytime use.
  • Sedating types like diphenhydramine (25-50mg daily) or hydroxyzine (25–50 mg daily) may help if itching affects sleep.
• Gabapentin or pregabalin may be used if antihistamines aren’t effective. These medications work by calming itch signals in the body and brain, though evidence is limited to small studies
• Oral Steroid may be used for short-term relief in severe cases.

Treatment depends on how severe the itching is. Mild symptoms may improve with moisturizers or antihistamines, while more serious cases might need stronger medications or a temporary pause in your cancer therapy to help manage the itch.