Keloid Scar: Symptoms, Types, Causes and Treatment

Keloid scars are more than just a cosmetic nuisance; they represent a complex wound healing disorder that can profoundly impact quality of life. Beyond their appearance, keloids can cause physical discomfort, emotional distress, and functional issues. Understanding keloid scars—their symptoms, different forms, root causes, and available treatments—is crucial for both patients and healthcare providers. This comprehensive guide provides an up-to-date, evidence-based overview of keloid scars to support informed decision-making and holistic care.

Symptoms of Keloid Scar

Keloid scars present with a broad spectrum of symptoms that go far beyond visual concerns. For many, the physical sensations and emotional toll are as significant as the scar’s appearance. Recognizing the full range of symptoms is the first step to seeking effective support and treatment.

Symptom	Description	Impact	Sources
Itch	Persistent, often intense pruritus	Discomfort, sleep disruption	1,2,5
Pain	Tenderness, burning, or aching	Reduced function, distress	1,2,3
Growth	Raised, expanding scar tissue	Physical deformity	3,9,13
Psychosocial	Anxiety, appearance-related distress	Lowered quality of life	2,3,10

Table 1: Key Symptoms

Itch and Pain: The Overlooked Burden

Itch (pruritus) and pain are the most common and distressing symptoms among those with keloid scars. Studies show that up to 86% of keloid patients experience itch, which often concentrates at the scar’s edge. Pain, reported by nearly half of patients, is frequently located at the center of the keloid 1,5. These symptoms are not just bothersome; they can be severe, persistent, and resistant to standard therapies.

• Itch: Can be intense, leading patients to scratch, which may worsen the scar.
• Pain: Ranges from mild tenderness to severe burning or aching.
• Location: Itch is usually peripheral, pain is more central 1.

Physical Growth and Deformity

Keloids are defined by their excessive, raised, and often spreading growth. Unlike normal scars, keloids extend beyond the original wound boundaries and can invade surrounding healthy skin. This invasive growth can result in visible and sometimes functionally limiting deformities 9,13.

Psychological and Emotional Impact

The visible nature of keloids, especially on exposed areas like the face, neck, or hands, can cause significant appearance-related anxiety, social withdrawal, and emotional distress. Studies highlight a marked impairment in emotional well-being, with pain and itch being the strongest predictors of decreased quality of life 2,3,10.

• Emotional distress: Includes embarrassment, low self-esteem, and depression.
• Social avoidance: Some patients avoid social situations or certain clothing to hide scars 3.

Functional Impairments

When keloids develop over joints or mobile areas, they can restrict movement, cause contractures, and interfere with daily activities. Even when hidden, the symptoms and discomfort can disrupt sleep, work, and social life 3.

Types of Keloid Scar

While all keloids share common characteristics, they can differ in appearance, behavior, and clinical course. Recognizing the main types can help tailor management strategies and set realistic expectations.

Type	Appearance/Pattern	Typical Location	Sources
Flat	Superficial, spreading	Chest, shoulders	9,13
Bulging	Raised, dome-like	Earlobes, jaw, arms	9,13
Linear	Elongated, follows wound	Surgical sites	7,9
Nodular	Firm, nodular clusters	Various sites	9

Table 2: Types of Keloid Scars

Flat (Superficial-Spreading) Keloids

These keloids spread laterally, remaining relatively thin and wide. They often develop on areas like the chest, shoulders, or upper back, where skin tension is high. The flat type can cause significant itch and discomfort, and its wide spread can be cosmetically distressing 9,13.

Bulging (Raised) Keloids

Bulging keloids are thick, dome-shaped, and project prominently above the skin surface. They are commonly seen on the earlobes (after piercings), jawline, or upper arms. The raised nature makes them particularly visible and sometimes prone to trauma 9,13.

Linear Keloids

Linear keloids form along surgical incisions or lacerations. They can extend far beyond the original wound, creating a rope-like appearance. These are often seen after surgical procedures, particularly on keloid-prone anatomical sites 7,9.

Nodular Keloids

Nodular keloids present as clusters of firm, rounded nodules. They may develop within larger keloid plaques or as isolated lesions at various body sites. These nodules can be tender and are often associated with a more aggressive growth pattern 9.

Keloid Heterogeneity

Importantly, a single individual may have different types of keloids at various sites. The heterogeneity in appearance and growth behavior among keloids reflects the complexity of their underlying biology and local environmental influences 9.

Causes of Keloid Scar

The development of keloids is a multifactorial process involving genetic, environmental, and local factors. Understanding these causes sheds light on why some people are more prone to keloids and why prevention and treatment can be so challenging.

Cause	Mechanism/Trigger	Risk Factors	Sources
Genetic	Inherited predisposition	Family history, ethnicity	9,12,15
Local Injury	Deep skin trauma	Surgery, piercings, burns	6,9,13
Inflammation	Chronic dermal inflammation	Infection, acne, irritation	6,11,13
Mechanical	Skin tension, movement	Chest, shoulders, joints	4,12
Systemic	Hormonal, nutritional, autoimmunity	Adolescence, pregnancy	4,12

Table 3: Causes and Triggers

Genetic Susceptibility

Keloid formation has a strong genetic component. Certain ethnic groups—particularly those of African, Hispanic, and Asian descent—are at higher risk. A family history of keloids increases the likelihood of developing them, suggesting inherited genetic variants that predispose individuals to abnormal wound healing 9,12,15.

Local Injury and Depth of Trauma

Keloids arise following injuries that penetrate into the reticular dermis, the deeper layer of the skin. Common triggers include:

• Surgical incisions
• Body piercings (especially ear)
• Burns or lacerations
• Acne, folliculitis, chickenpox, or other inflammatory skin diseases 6,13

Superficial wounds that do not reach the deep dermis rarely result in keloid formation 6.

Chronic Inflammation

Ongoing inflammation in the dermal layer is central to keloid development. Prolonged or abnormal inflammatory responses—marked by increased cytokines and immune cell infiltration—drive the excessive production of fibroblasts and collagen, leading to raised, persistent scars 6,11.

Mechanical Factors

Areas of the body exposed to greater tension, movement, or friction (such as the chest/shoulders, jaw, and upper back) are more likely to develop keloids. Mechanical forces activate cellular pathways that promote fibroblast proliferation and collagen deposition, exacerbating scar growth 4,12.

Systemic and Hormonal Influences

Systemic factors, including hormonal changes (adolescence, pregnancy) and nutritional status, may influence keloid risk and progression. Autoimmunity and vascular factors have also been implicated, though their roles are less clearly defined 4,12.

Environmental and Epigenetic Factors

Emerging research suggests that epigenetic changes—alterations in gene expression without changes to DNA sequence—can contribute to keloid susceptibility and persistence. Environmental triggers, such as repeated trauma or infection, may interact with these genetic and epigenetic factors to drive keloid formation 12.

Treatment of Keloid Scar

Managing keloid scars is challenging due to their persistent, recurrent nature and diverse presentations. Successful treatment often requires a personalized, multimodal approach that balances efficacy with minimization of side effects.

Treatment	Modality/Action	Purpose/Effect	Sources
Corticosteroids	Injection, topical, tape	Reduce inflammation, size	14,16,17
5-Fluorouracil	Intralesional injection	Inhibit fibroblast activity	14,16,17
Surgery	Excision of keloid tissue	Remove bulk scar	7,10,14
Radiation	Post-surgical adjuvant	Prevent recurrence	7,14
Compression	Dressings/silicone sheeting	Reduce tension, flatten scar	7,14
Laser Therapy	Various laser types	Improve appearance, texture	14,17
Emerging/Adjunct	Imiquimod, botulinum toxin, etc	Target specific pathways	7,13,17

Table 4: Main Treatment Approaches

First-Line Therapies: Corticosteroids and Silicone

Corticosteroid injections (typically triamcinolone) are considered first-line therapy for most keloids. They work by reducing inflammation and suppressing abnormal fibroblast activity, which helps flatten the scar and relieve symptoms of itch and pain 14,16,17. Silicone gel sheets or dressings are often used in combination, providing a physical barrier and hydrating environment that can soften and reduce keloid size 14.

• Pros: Widely available, effective for many patients
• Cons: Up to 50% may be steroid-resistant; risk of skin atrophy, telangiectasia 16

Intralesional 5-Fluorouracil (5-FU) and Other Injections

5-FU is an antimetabolite drug that inhibits fibroblast proliferation. Intralesional 5-FU, alone or combined with corticosteroids, offers an alternative for steroid-resistant keloids or cosmetically sensitive areas, with a lower risk of skin thinning 16,17.

• May be combined with bleomycin or verapamil injections for synergistic effects 14.

Surgical Excision and Adjuvant Therapies

Surgical removal of keloid tissue can provide immediate relief from bulk and deformity, but keloids have a very high rate of recurrence after surgery alone. To minimize this, immediate post-excision radiation therapy is often used as an adjunct, significantly reducing recurrence rates by targeting residual abnormal fibroblasts 7,10,14.

• Pressure dressings and silicone sheeting post-operatively can also help prevent regrowth 14.

Laser and Light-Based Therapies

Various types of lasers (e.g., pulsed dye laser) can improve keloid redness, thickness, and texture, especially when combined with topical steroids to enhance drug penetration 14,17. Photodynamic therapy is another emerging approach under investigation.

Other and Emerging Treatments

• Cryotherapy: Freezing the keloid, often used for smaller or early lesions.
• Imiquimod cream: Immunomodulating agent applied post-excision to reduce recurrence.
• Botulinum toxin A: May reduce scar tension and fibroblast activity.
• Novel approaches: Target growth factors, cytokines, and even use of autologous fat grafting or stem cell therapies 7,13,17.

Multimodal and Individualized Approach

No single treatment offers a cure or universally low recurrence rate. The best results are often achieved by combining modalities, tailored to the scar’s type, location, patient history, and previous treatments 14,17. Newer therapies continue to emerge, aiming for better symptom control and lower recurrence.

Conclusion

Keloid scars are a complex, multifaceted condition with significant physical, functional, and psychosocial impacts. Early recognition, patient-centered management, and a multimodal treatment approach are essential for optimal outcomes.

Key Takeaways:

• Symptoms go beyond appearance: itch, pain, growth, and emotional distress are common and impactful.
• Types of keloids include flat, bulging, linear, and nodular forms, each with distinctive features.
• Causes involve a combination of genetic predisposition, local injury, chronic inflammation, mechanical forces, and systemic factors.
• Treatment is challenging due to high recurrence; best results come from combined approaches—corticosteroids and silicone, 5-FU, surgery with adjuvant therapy, compression, laser, and emerging modalities.
• Holistic care that addresses both physical and psychological aspects is vital for improving quality of life in those affected by keloid scars.

By understanding the full spectrum of keloid scars, patients and clinicians can work together to choose the most effective and compassionate treatment strategies.