Makindo Medical Notes

Some studies suggest that increased expression of transforming growth factor-beta (TGF-β), a cytokine involved in wound healing, plays a role in keloid formation.

Pathophysiology

• Keloids are the result of excessive fibroblast activity and collagen production in response to skin injury or inflammation.
• Unlike hypertrophic scars, which stay within the boundary of the original wound, keloids grow beyond the wound edges and may continue expanding for months or years.
• The collagen fibers in keloids are disorganized and arranged in a haphazard manner, contributing to the firm, raised appearance.
• There is a genetic predisposition to keloid formation, especially in people with darker skin tones, indicating that abnormal wound healing may be genetically controlled.

Epidemiology

• Keloids are seen more with darker skin tones, African, Hispanic, and Asian descent.
• Occur at any age but are most commonly seen in people aged 10 to 30 years old.
• Decrease with age, as the ability of the skin to form them generally diminishes after 30 years old.
• Genetics as keloids tend to run in families with keloids after skin trauma.
• May show a slightly higher prevalence in women.

Differential Diagnosis: Several other conditions can resemble keloids

• Hypertrophic scars: These are similar to keloids but are confined within the borders of the original injury and do not continue to grow after a year.
• Squamous Cell Carcinoma (SCC): Keloids need to be distinguished from SCC, particularly in cases where there is an ulcerating or unusual appearance.
• Dermatofibroma: A benign skin growth that can resemble a small, firm nodule like a keloid.
• Melanocytic nevi: Benign moles that may be mistaken for a keloid if they are raised or pigmented.
• Basal Cell Carcinoma (BCC): A common skin cancer that can sometimes be mistaken for a keloid, especially when it presents as a raised lesion.
• Other skin lesions: Including warts (verruca vulgaris) and infected cysts, which might share a similar appearance.

Clinical Presentation

• Firm, shiny papules or nodules that are typically skin-colored, pink, red, or red-bluish in appearance.
• Most commonly arise from skin injuries such as piercings, surgical scars, acne, or burns, though they can also develop spontaneously, often with no obvious trauma.
• The lesion typically extends beyond the margins of the original injury, continuing to grow for months or even years, sometimes forming claw-like extensions or irregular shapes.
• Can be pruritic (itchy), painful, or tender to touch, and may be associated with a burning or stinging sensation.
• Commonly found on the earlobes, shoulders, chest (sternum), back (scapular area), and upper arms, but they can appear anywhere on the body except for the palms and soles.
• As they grow, keloids may affect mobility if they form over joints or interfere with other body functions.

Investigations

• Diagnosis of keloids is typically clinical, based on their characteristic appearance and growth pattern.
• A skin biopsy is usually not required unless there is uncertainty in the diagnosis or suspicion of malignancy (e.g., when the lesion behaves unusually or has a rapid growth pattern).
• In cases of suspected infection or other complications, cultures may be taken to rule out bacterial or fungal infections.
• In some cases, imaging (e.g., ultrasound) may be used to evaluate the depth and extent of the keloid if surgical excision is considered.

Management

• Conservative management: In cases where keloids are asymptomatic or not cosmetically concerning, no treatment may be necessary.
• Intralesional corticosteroid injections: The first-line treatment to reduce inflammation, flatten the keloid, and relieve associated symptoms like itching or pain. Multiple sessions may be required for optimal results.
• Cryotherapy: Freezing the keloid with liquid nitrogen can be effective, especially for smaller lesions.
• Silicone sheets or gel: Compression therapy, using silicone sheets or gels, can help flatten the keloid over time by reducing collagen production and promoting reabsorption of excess tissue.
• Excision: Surgical removal of keloids is considered for large or persistent lesions, especially when other treatments have failed. However, excision carries a risk of recurrence, and adjunctive treatments (e.g., corticosteroids or cryotherapy) are often used post-excision to reduce this risk.
• Laser therapy: Laser treatments can help reduce the size, color, and texture of keloids, though they are often used in combination with other therapies.
• Radiotherapy: In rare cases, low-dose radiotherapy is used to prevent recurrence after surgical excision of large keloids.