A clinical challenge

Keloids and hypertrophic scars result from perturbations in the wound healing process that lead to excess collagen synthesis and deposition [1]. Besides frequently being pruritic and painful, such pathological scarring can cause disfigurement, functional impairment, emotional distress and psychological damage [1, 2].

Specific areas of the body that are relatively more susceptible to developing keloids or hypertrophic scars include the sternal skin, earlobes (piercings), shoulders and upper arms (vaccinations) and cheeks (acne) [1, 2]. Keloids occur more commonly in Black, Hispanic and Asian individuals than in Caucasians, with darker pigmented skin carrying a 15-fold increased risk [1, 2]. There is some evidence for a genetic predisposition, although the precise mode of inheritance is not yet clear [1]. Although keloids can occur at any age, they are more common in individuals aged <30 years [2], with their incidence peaking at 15–24 years [1]. Individuals with elevated hormone levels (e.g. during puberty or pregnancy) may also have an increased risk of developing keloids [2].

This article provides a summary of the clinical challenges in the prevention and treatment of keloids and hypertrophic scars, as reviewed by Trace et al [1].

Prevention is best

Given the challenges in treating pathological scarring, efforts should be made to prevent the occurrence of keloids and hypertrophic scars whenever possible, although this may not always be practical to achieve [1]. Prior to any surgical procedure, physicians should establish if the patient has had any previous problems with scarring, and the potential for keloids or hypertrophic scars to develop should be discussed. Ear piercing and other elective procedures (such as elective mole removal) should be discouraged in patients with a known predisposition to pathological scarring [2]. The use of proper atraumatic surgical technique is critical to help minimize the risks of keloids or hypertrophic scars; wounds should be closed under minimal tension [1, 3]. For patients considered at high risk of developing pathological scarring, preventive measures, such as the prophylactic use of silicone-based products, is recommended [1].

Establish realistic expectations with the patient

The treatment of keloids and hypertrophic scars remains very challenging [1–3]. A wide variety of therapeutic modalities are available (Tables 1, 2, 3), with each treatment option having a varying degree of effectiveness [1–3]. Largely due to the limited amount of data available from well-designed randomized controlled trials, there is no clinical consensus regarding the most appropriate treatment for these lesions [1, 2]. The best evidence supports the use of intralesional steroid injections (Table 1) and silicone gel sheeting (Table 2) as first-line options [1, 2]. Cryotherapy (Table 3) may be effective for smaller lesions (e.g. acne keloids) [2]. In general, outcomes appear to be improved when combination therapy is used [1–3].

Table 1 Summary of pharmacological modalities for the prevention and treatment of pathological scarring, as reviewed by Trace et al. [1]
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Table 2 Summary of non-invasive modalities for the prevention and treatment of pathological scarring, as reviewed by Trace et al. [1]
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Table 3 Summary of surgical, cryotherapy and laser treatment of pathological scarring, as reviewed by Trace et al. [1]
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Further therapies are available or emerging

Less common treatments for keloids and hypertrophic scars include interferon-α-2b, mitomycin C, onion extract, radiotherapy, vitamins A and E, verapamil, polyurethane dressing, botulinum toxin and photodynamic therapy [1]. Emerging therapies that have shown promise include topical and intradermal immune modulators, anti-transforming growth factor-β antibodies, and micro RNA (miRNA) and small interfering RNA (siRNA)-based methods [1]. Nonetheless, it is clear that keloids and hypertrophic scars still provide significant clinical challenges, and further research in this field is required [1].