Radiation Dermatitis (Radiation Skin Reactions)

Last updated: January 2025 | Medical Reviewer: Oncol.net Editorial Board

Overview

Radiation dermatitis is skin inflammation and damage that occurs in the area being treated with radiation therapy (the treatment field). It is the most common side effect of radiation therapy, occurring in nearly all patients to some degree. The severity ranges from mild redness and dryness to significant skin breakdown with open wounds.

The skin is particularly vulnerable to radiation because skin cells divide rapidly to replace the outermost layer that is constantly being shed. Radiation targets rapidly dividing cells, which is why it affects both cancer cells and healthy skin cells in the treatment area.

With proper prevention and management, most patients experience only mild to moderate skin reactions that heal completely within 2-4 weeks after treatment ends. Severe reactions (Grade 3-4) are less common with modern radiation techniques but require intensive management when they occur.

Why Radiation Causes Skin Damage

Cellular Mechanism

• Direct DNA damage: Radiation damages DNA in both cancer cells and normal cells in its path
• Rapidly dividing cells affected: Basal keratinocytes (skin cells) in the epidermis divide frequently, making them vulnerable
• Cumulative effect: Damage accumulates over multiple treatments (fractions)
• Impaired repair: Radiation also damages blood vessels and reduces the skin's ability to repair itself
• Inflammatory response: Release of inflammatory cytokines contributes to redness, swelling, and pain

Timeline of Skin Changes

Radiation dermatitis follows a predictable pattern, though timing and severity vary by individual:

Incidence and Risk Factors

Overall Incidence

• Any dermatitis: 95% of patients experience some degree of skin reaction
• Grade 1 (mild): 60-80% of patients
• Grade 2 (moderate): 30-50% of patients
• Grade 3 (severe): 10-20% of patients
• Grade 4 (life-threatening): <2% with modern techniques (rare)

Factors That Increase Risk of Severe Reactions

Treatment-Related Factors

• Higher total radiation dose: >50-60 Gy increases risk
• Larger daily fractions: Higher dose per treatment session
• Treatment site: Areas with skin folds or friction have higher risk
  • Highest risk areas: Inframammary fold (under breast), groin, perineum, axilla (armpit), neck folds
  • Common treatment sites: Breast, chest wall, head/neck, pelvis, perineum
• Concurrent chemotherapy: Especially radiosensitizing drugs (cisplatin, 5-FU, gemcitabine, cetuximab)
• Bolus material: Used to increase surface dose, intentionally increases skin reaction
• Electron beam therapy: Treats superficial areas, higher skin dose

Patient-Related Factors

• Skin type: Fair skin (Fitzpatrick Type I-II) more susceptible to severe reactions; darker skin may have more pronounced pigmentation changes
• Body habitus: Obesity increases risk (more skin folds, friction)
• Smoking: Impairs healing, increases severity
• Poor nutrition: Low protein, vitamin deficiencies delay healing
• Connective tissue disorders: Lupus, scleroderma increase radiation sensitivity
• Genetic factors: Some individuals are more radiosensitive (ATM gene mutations, etc.)
• Previous surgery in area: Scarring, compromised blood flow
• Chronic sun damage: May increase sensitivity

Grading of Radiation Dermatitis

Radiation skin reactions are graded using standardized criteria, most commonly the Common Terminology Criteria for Adverse Events (CTCAE) or RTOG (Radiation Therapy Oncology Group) criteria. Grading helps guide treatment decisions.

Acute vs. Late Effects

Acute Radiation Dermatitis (During and Shortly After Treatment)

• Timing: Occurs during treatment and up to 90 days after completion
• Features: Erythema, desquamation, pain, edema
• Mechanism: Direct cellular damage and inflammatory response
• Resolution: Usually resolves 2-4 weeks after treatment completion
• Reversible: Skin typically returns to near-normal appearance

Late Radiation Effects (Months to Years After Treatment)

• Timing: Develops >90 days after treatment, can continue to evolve for years
• Permanent pigmentation changes:
  • Hyperpigmentation (darkening) - most common
  • Hypopigmentation (lightening) - may occur after initial darkening fades
  • More pronounced in individuals with darker skin
• Telangiectasia: Visible dilated blood vessels (small red spider veins)
• Fibrosis: Skin may become thicker, less elastic, or firm
• Chronic dryness: Reduced oil and sweat gland function
• Atrophy: Skin may become thinner in treated area
• Permanent hair loss: Hair follicles destroyed at higher doses
• Increased sun sensitivity: Treated skin remains more vulnerable to sun damage permanently

Common Treatment Sites and Specific Considerations

Breast Cancer Radiation

• Most common site for radiation dermatitis
• High-risk area: Inframammary fold (under breast) - skin fold creates friction, moisture, and increased dose
• Management: Keep fold dry, use absorbent pads, lift breast to air out fold
• Special considerations:
  • Post-mastectomy radiation (chest wall) may have less severe reactions than intact breast
  • Larger breast size increases risk due to more skin folding
  • Deodorant controversy: Most centers allow aluminum-free deodorants during treatment; aluminum-containing traditionally avoided (may increase dose) but evidence limited

Head and Neck Cancer Radiation

• High risk due to high doses and concurrent chemotherapy (often used)
• Problem areas: Posterior neck, skin folds around chin/jaw
• Complications: Facial edema, beard loss (men), difficulty shaving
• Management challenges: Difficult to avoid friction (clothing collars, pillows during sleep)
• Concurrent mucositis: Mouth and throat sores often accompany skin reactions

Chest Wall Radiation (Lung Cancer, Esophageal Cancer)

• Generally less severe than breast radiation (flatter surface, less folding)
• May involve larger treatment fields
• Watch for reactions in axilla (armpit) if included in field

Pelvic Radiation (Rectal, Anal, Gynecologic, Prostate Cancer)

• High-risk areas: Groin creases, perineum (area between genitals and anus), buttock crease
• Challenges: Difficult to keep dry, friction from walking and sitting, hygiene complications
• Perineal skin: Very sensitive, prone to moist desquamation
• Management: Gentle cleansing after bowel movements (avoid harsh wiping), barrier creams, sitz baths

Total Body Irradiation (TBI) - Bone Marrow Transplant

• Entire skin surface treated
• Moderate erythema and dry desquamation common
• Severe reactions rare (lower doses per fraction)
• Healing complicated by low blood counts and immunosuppression

Prevention Strategies

General Skin Care Guidelines

The Moisturizer Controversy: When to Apply

There has been historical controversy about whether moisturizers should be used during radiation and when to apply them:

Timing on Treatment Days:

• Do NOT apply moisturizer within 2-4 hours BEFORE radiation treatment (may interfere with beam delivery)
• Apply moisturizer AFTER radiation treatment (wait at least 2 hours to allow skin to cool)
• On non-treatment days, apply moisturizer 2-3 times daily

Skin Care by Treatment Site

Breast/Chest Wall

• Lift breast to air out inframammary fold daily
• Place soft cotton cloth or gauze pad under breast to absorb moisture
• Wear soft cotton bra without underwire (sports bra or sleep bra)
• Some patients find going braless at home helpful for reducing friction
• Cornstarch in fold (if completely dry) - controversial, some centers avoid due to infection risk if skin breaks down

Head and Neck

• Men: Do not shave; use electric trimmer if necessary
• Avoid shirt collars that rub neck
• Use silk or satin pillowcase to reduce friction during sleep
• Keep posterior neck clean and dry

Pelvic/Perineal

• Cleanse gently with water after bowel movements (use peri-bottle or bidet)
• Pat dry with soft toilet paper or air dry
• Wear loose cotton underwear
• Sitz baths (lukewarm, not hot) can soothe irritation
• Barrier creams (zinc oxide, Desitin) to protect from stool/urine

Recommended Products

Moisturizers and Skin Protectants

Products to AVOID During Treatment

Treatment by Grade

Specific Topical Treatments

Silver Sulfadiazine 1% Cream (Silvadene)

• Mechanism: Broad-spectrum antimicrobial, prevents infection in moist desquamation
• Use: Grade 2-3 dermatitis with moist desquamation
• Application: Apply thin layer to affected areas 1-2 times daily
• Cleansing: Gently remove previous application before reapplying
• Contraindication: Sulfa allergy, pregnancy (third trimester), infants <2 months
• Side effects: May cause temporary skin discoloration (gray), burning sensation
• Availability: Prescription required

Hydrocortisone 1% or 2.5%

• Mechanism: Anti-inflammatory, reduces erythema and itching
• Use: Grade 1-2, applied to dry, intact skin (not open areas)
• Application: Thin layer twice daily
• Caution: Do not use on broken skin or infected areas; long-term use may thin skin
• Availability: 1% over-the-counter; 2.5% prescription

Hydrogel Dressings

• Examples: Vigilon, AquaSite, IntraSite Gel, Radiagel
• Mechanism: Maintain moist wound environment, cooling effect
• Use: Grade 2-3 moist desquamation
• Application: Apply to wound, cover with non-adherent dressing
• Benefits: Soothing, promotes healing, less painful dressing changes
• Can be refrigerated for extra cooling relief

Barrier Creams (Zinc Oxide, Desitin, Calmoseptine)

• Use: Perineal/groin area - protect from urine and stool
• Application: Apply AFTER radiation treatment each day
• Cleanse before radiation: Remove thoroughly before each treatment
• Note: Zinc oxide is a metal - avoid before radiation, okay after

Managing Complications

Infection

Broken skin (moist desquamation) is vulnerable to bacterial infection.

Management:

• Contact radiation oncology team immediately
• Culture of drainage may be needed
• Oral antibiotics (cephalexin, dicloxacillin, or others based on culture)
• Continue gentle cleansing and silver sulfadiazine
• May require IV antibiotics if severe (cellulitis, systemic symptoms)

Severe Pain

• Causes: Nerve damage, inflammation, skin breakdown
• Assessment: Rate pain 0-10 scale
• Management:
  • Mild (1-3): Acetaminophen, ibuprofen
  • Moderate (4-6): Tramadol, codeine, low-dose oxycodone
  • Severe (7-10): Oxycodone, morphine, fentanyl patches
  • Neuropathic component: Gabapentin 300-900 mg/day or pregabalin
  • Topical: Lidocaine gel 2-5%, lidocaine/prilocaine cream
• Consider treatment break if pain is interfering with quality of life despite adequate analgesia

Pruritus (Itching)

• Common with dry desquamation and healing phase
• Management:
  • Oral antihistamines: Cetirizine (Zyrtec) 10 mg daily, loratadine (Claritin) 10 mg daily, or diphenhydramine (Benadryl) 25-50 mg at bedtime
  • Topical hydrocortisone 1% to intact skin
  • Cooling measures: Cool compresses, refrigerated aloe or hydrogel
  • Maintain moisturization
  • Trim nails short to minimize damage from scratching
  • Cotton gloves at night if scratching during sleep

Lymphedema

• Swelling due to lymphatic system damage (especially with lymph node radiation)
• Risk increases with infection, trauma, or chronic inflammation
• More common in extremities (arm after breast/axillary radiation, leg after pelvic radiation)
• Prevention: Protect skin from injury, treat infections promptly
• Management: Compression garments, manual lymphatic drainage, physical therapy

When to Contact Your Healthcare Team

After Treatment: Recovery and Long-Term Care

Immediate Post-Treatment (Weeks 1-4 After Last Radiation)

• Expect temporary worsening: Reactions may peak 1 week after treatment completion (normal "recall" phenomenon)
• Continue all skin care: Don't stop just because treatment is done
  • Keep moisturizing 2-3 times daily
  • Continue silver sulfadiazine if you have moist desquamation
  • Maintain gentle cleansing
  • Continue sun protection
• Healing timeline:
  • Erythema begins fading in 1-2 weeks
  • Dry desquamation improves in 2-3 weeks
  • Moist desquamation heals (re-epithelializes) in 2-4 weeks
  • New skin may be pink or lighter initially
• Follow-up: See radiation oncologist 4-6 weeks after treatment completion to assess healing

Long-Term Skin Changes (Months to Years)

• Pigmentation changes:
  • Hyperpigmentation (darkening) very common - may fade over 6-12 months but often permanent to some degree
  • Hypopigmentation (lightening) may develop later
  • Treatment field may remain visible as slightly different color
• Skin texture changes:
  • May feel thicker (fibrosis) or thinner (atrophy)
  • Less elastic than before treatment
  • Reduced oil and sweat production (chronic dryness)
• Telangiectasia: Small visible blood vessels may appear months to years later (cosmetic, not harmful)
• Hair loss: Usually permanent at doses >45-50 Gy
• Increased sun sensitivity: Lifelong - treated skin burns more easily

Lifelong Skin Care in Treated Area

• Sun protection: Essential forever
  • Broad-spectrum SPF 30+ sunscreen daily (mineral-based preferred)
  • Reapply every 2 hours if outdoors
  • Protective clothing, hats
  • Seek shade
• Moisturize: Continue daily moisturizing to combat chronic dryness
• Gentle care: Treated skin remains more vulnerable to injury
• Monitor for changes: Report any new lumps, sores that don't heal, or color changes to your doctor
• Secondary cancers: Very rare but small increased risk of skin cancer in treated field years later - monitor

Emerging Treatments and Research

Agents Under Investigation

• Topical corticosteroids (prophylactic): Studies examining whether starting steroids from day 1 prevents severe reactions
• Hyperbaric oxygen: May help severe or non-healing wounds (limited access, expensive)
• Growth factors: Recombinant human epidermal growth factor, platelet-derived growth factor
• Anti-inflammatory agents: Various topical and oral agents being studied
• Laser therapy: For treatment of telangiectasia

What Doesn't Work (Despite Popular Belief)

• Vitamin E cream: No proven benefit, may worsen reactions in some studies
• Baby powder/talc: Not helpful, may cake and irritate skin
• Antibiotic ointments (prophylactic): Not recommended unless infection present

Special Populations

Re-Irradiation (Second Course of Radiation to Same Area)

• Higher risk of severe reactions due to cumulative dose
• Skin may have reduced tolerance from first treatment
• Requires careful monitoring and possibly lower doses
• Proactive skin care from day 1 essential

Patients with Connective Tissue Disorders

• Conditions: Lupus, scleroderma, dermatomyositis, Sjogren's syndrome
• Risk: Significantly increased radiosensitivity
• Complications: More severe acute reactions, worse late effects
• Management: Consider dose reduction, closer monitoring, aggressive skin care

Darker Skin (Fitzpatrick Types IV-VI)

• Acute reactions similar to lighter skin
• Post-inflammatory hyperpigmentation more pronounced and longer-lasting
• Sun protection equally important
• Pigmentation changes may be more distressing cosmetically

Frequently Asked Questions

Will everyone getting radiation have skin reactions?

Almost all patients (95%) will experience some degree of skin change in the treatment field, but severity varies greatly. Mild redness and dryness are nearly universal, but severe skin breakdown (Grade 3) occurs in only 10-20% of patients. Factors affecting severity include treatment site, dose, individual sensitivity, and how well you care for your skin.

When will my skin reactions start and how long will they last?

Most patients notice initial changes around weeks 2-3 of treatment. Reactions peak toward the end of treatment and may worsen slightly for up to 1 week after your last radiation session (this is normal). Healing typically begins 2 weeks post-treatment, with most acute reactions resolving by 4-6 weeks after completion. Late changes (pigmentation, texture) develop over months and may be permanent.

Should I use moisturizer during radiation or wait until after?

Current evidence supports using aqueous-based moisturizers throughout treatment. Apply moisturizer 2-3 times daily on non-treatment days. On treatment days, do NOT apply moisturizer within 2-4 hours BEFORE radiation, but DO apply AFTER your daily treatment (wait at least 2 hours). This helps maintain skin hydration without interfering with radiation delivery.

Can I use Aquaphor or Vaseline during radiation?

This is controversial and policies vary by radiation center. Historically, petroleum-based products were avoided during active radiation due to concerns about increasing surface dose. Current evidence suggests they are safe when applied AFTER daily radiation treatments. Check with your radiation oncology team for their specific recommendations.

Why does skin get worse after treatment is done?

This "recall phenomenon" is normal and occurs because radiation effects continue to accumulate for about 1 week after the last treatment. Your skin is responding to the cumulative dose. Don't panic - this temporary worsening is expected. Continue your skin care routine diligently, and healing will begin within 1-2 weeks.

Is radiation dermatitis the same as a burn?

Radiation dermatitis is sometimes called a "radiation burn," but the mechanism is different from thermal burns (fire, heat). Radiation causes cellular DNA damage and inflammation rather than direct heat injury. However, the appearance can be similar (redness, blistering, skin loss), and management principles overlap (wound care, prevent infection, promote healing).

Can I swim during radiation treatment?

Most radiation oncologists recommend avoiding chlorinated pools during active treatment, as chlorine can irritate compromised skin. Salt water (ocean) swimming is usually acceptable if your skin is intact (no open areas). After treatment completion and skin healing, swimming is fine. Always rinse treated area gently with fresh water after swimming and reapply moisturizer.

What about deodorant during breast radiation?

You can use deodorant, but choose aluminum-free products. Traditional antiperspirants contain aluminum, which was historically avoided due to concern it might increase radiation dose (limited evidence for this concern, but still commonly recommended). Many natural/aluminum-free deodorants are available (Tom's of Maine, Native, Crystal, etc.). If the axilla (armpit) is in your treatment field and develops significant irritation, you may need to stop using deodorant temporarily.

Will the skin in my treatment area be permanently different?

Some changes are likely permanent but usually subtle. Common long-term effects include slight darkening or lightening of skin color, small visible blood vessels (telangiectasia), altered texture (slightly thicker or thinner), reduced oil/sweat production, and permanent hair loss in the area. These changes are typically cosmetic rather than functional. The treated area will always be more sun-sensitive, requiring lifelong sun protection.

Should I take a break from radiation if my skin gets bad?

Treatment breaks are considered for Grade 3 reactions (widespread moist desquamation, severe pain) that aren't improving or are progressing rapidly. Breaks are typically 3-7 days to allow healing. However, radiation oncologists try to avoid breaks when possible because they may reduce cancer treatment effectiveness. Your team will balance skin toxicity against treatment efficacy. Always discuss your skin concerns at weekly visits.

Are there medications I can take to prevent skin reactions?

Currently, no systemic medications are proven to prevent radiation dermatitis. Management relies on good topical skin care. Prophylactic corticosteroids are being studied but not yet standard. Oral supplements (vitamin E, antioxidants) have not shown consistent benefit and are not routinely recommended. Your best prevention is diligent adherence to gentle skin care practices from day 1.

Why can't I use my regular scented lotion?

Fragrances, alcohols, and other chemicals in scented products can irritate radiation-damaged skin. During treatment, your skin's protective barrier is compromised, making it more sensitive to these irritants. Fragrance-free, hypoallergenic products minimize risk of allergic reactions and further irritation, promoting better healing.

Will radiation dermatitis increase my risk of skin cancer?

There is a very small increased risk of secondary skin cancer (basal cell carcinoma, squamous cell carcinoma, or rarely melanoma) in previously irradiated skin, but this risk develops many years after treatment and is low overall. The cancer control benefit of radiation far outweighs this small risk. Lifelong sun protection and annual skin monitoring help detect any concerning changes early.

Sources and References

• National Cancer Institute. Radiation Therapy Side Effects: Skin and Nail Changes. 2024.
• Radiation Therapy Oncology Group (RTOG) Acute Radiation Morbidity Scoring Criteria
• Common Terminology Criteria for Adverse Events (CTCAE) v5.0
• Chan RJ, Webster J, Chung B, et al. Prevention and treatment of acute radiation-induced skin reactions: a systematic review and meta-analysis of randomized controlled trials. BMC Cancer. 2014
• Salvo N, Barnes E, van Draanen J, et al. Prophylaxis and management of acute radiation-induced skin reactions: a systematic review of the literature. Curr Oncol. 2010
• Hymes SR, Strom EA, Fife C. Radiation dermatitis: clinical presentation, pathophysiology, and treatment 2006. J Am Acad Dermatol. 2006
• Pommier P, Gomez F, Sunyach MP, et al. Phase III randomized trial of Calendula officinalis compared with trolamine for the prevention of acute dermatitis during irradiation for breast cancer. J Clin Oncol. 2004
• Wong RK, Bensadoun RJ, Boers-Doets CB, et al. Clinical practice guidelines for the prevention and treatment of acute and late radiation reactions from the MASCC Skin Toxicity Study Group. Support Care Cancer. 2013
• American Society for Radiation Oncology (ASTRO). Radiation Therapy for Breast Cancer: Management of Side Effects. 2024.