|Year : 2019 | Volume
| Issue : 1 | Page : 29-32
Keloids coexisting with vitiligo − A rare case series
Rayna T Velurethu, Murugesh B Shamanur, Viswanath K Belluli
Department of Dermatology, Venereology and Leprosy, JJM Medical College, Davangere, Karnataka, India
|Date of Web Publication||4-Jul-2019|
Dr. Rayna T Velurethu
Room No. 9, Skin OPD, Bapuji OPD Hospital, MCC B Block, Davangere 577004
Source of Support: None, Conflict of Interest: None
Background Hypertrophic scars and keloid scars are a result of abnormal wound healing, in which the key feature is the excess collagen fiber secretion by fibroblasts that have been stimulated by α-melanocyte-stimulating hormone, produced by the melanocytes. Vitiligo is a common depigmenting skin disorder characterized by a total absence of the melanocytes microscopically. The observation that keloids do not occur in albinous or vitiligo patches has consolidated the theory that the melanocytes are linked to the proliferation of fibroblasts, which are central to the development of keloids. To the best of our knowledge, there is only one previous report of keloids arising over vitiligo patch.
Case Series We observed three patients with keloids arising from a pre-existing vitiligo patch. All keloids were preceded by trauma. Two out of the three patients showed leucotrichia in the patch where keloid had developed. In two of our patients, we observed both a reduction in the size of the keloids as well as the repigmentation of the patches at a shorter span of time on using 5-fluorouracil as a treatment modality.
Discussion According to a few studies, the number and activity of the melanocytes in the skin can be postulated to play a dominant role in pathological scar formation. However, we found three patients in whom keloids had developed on vitiligo patches. This suggests that fibroblast proliferation in keloids may not be completely dependent on just stimulation by αMSH secreted by the melanocytes, and that several other pathways may be at play to stimulate the FGF and TGF factors, which are considered central to the development of keloid.
Keywords: αMSH, keloid, vitiligo
|How to cite this article:|
Velurethu RT, Shamanur MB, Belluli VK. Keloids coexisting with vitiligo − A rare case series. Pigment Int 2019;6:29-32
| Introduction|| |
Hypertrophic scars and keloid scars are caused by abnormal wound healing, the key feature of which is excess collagen fiber secretion by fibroblasts that have been stimulated by the melanocytes. The melanocytes can stimulate the growth and proliferation of fibroblasts, increase collagen synthesis and extracellular matrix deposition, activate the TGF-β signaling pathway, and promote the development of pathological scarring. This may be dependent on melanocyte number, distribution in the skin, activation status, and certain other factors. However, a keloid arising from a preexisting vitiligo patch points toward yet another unidentified pathway involved in keloid formation.
| Case history|| |
A 21-year-old female presented to us with depigmented patches over the face, as well as the upper and lower limbs, which were of 4 years duration. Vitiligo lesions appeared spontaneously, and the patient also reported a recent appearance of new vitiliginous lesions at the site of trauma. She also reported a post-traumatic asymptomatic swelling on one of the facial patches of vitiligo since 6 months. The patient had not applied any irritants at the time of the appearance of this swelling. The swelling was gradually progressive and painless. Family history for keloids and vitiligo was negative. On examination, she was found to have multiple well-defined depigmented patches on the dorsum of the feet, lips, and face. Leucotrichia was not present. A well-defined, nontender, firm plaque of about 3 cm × 4 cm was noted on the depigmented patch on the right cheek [[Figure 1]]. The margins were irregular and were observed to be encroaching on the surrounding skin. On the basis of the clinical findings, the patient was diagnosed with vitiligo vulgaris and keloid, which was confirmed after correlating with histopathological findings.
|Figure 1 A well-defined, nontender, firm plaque with irregular margins of about 3 cm × 4 cm on the depigmented patch on the right cheek|
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The patient was treated with NB-UVB for the vitiligo patches and with once daily local application of topical 5% fluorouracil for the keloid. Both, the depigmented patch and the keloid, responded to the therapy in a span of 3 months.
A 23-year-old male patient with vitiligo vulgaris of 2 years duration presented with an asymptomatic swelling limited to a depigmented patch of vitiligo on the right knee, which occurred 3months previously, following a fall. The patient had not received any treatment for vitiligo in the past one and half years. Family history for vitiligo and keloids was negative. On examination, the patient had multiple depigmented patches on the trunk, as well as the upper and lower limbs. A depigmented patch on the right knee with leucotrichia was found to have a firm, nontender, erythematous plaque measuring about 2 cm × 3 cm with irregular extensions and border limited to the depigmented patch. The patient was diagnosed with vitiligo vulgaris and keloid on the basis of clinical and histological findings [[Figure 2]]. The keloid was treated with intralesional triamcinolone 10 mg/ml every 3 weeks. The lesion showed complete flattening in a span of 3 months.
|Figure 2 Fontana-Masson stain of the lesion at 10× magnification showing a remarkable absence of melanocytes in the epidermis and the bundles of collagen in the dermis|
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A 36-year-old male patient reported with multiple depigmented patches on the upper and lower limbs and the trunk, which were of 2 years duration. The patient also reported developing asymptomatic swelling on the depigmented patches, which were of 8 months duration, following a bike accident. There was no history regarding the application of irritants or phototherapy at the time of the appearance of swelling. On examination, the patient was found to have multiple depigmented patches with leucotrichia and perifollicular pigmentation on the trunk and extremities. Two firm, irregular, erythematous plaques of about 4 cm × 5 cm and 5 cm × 6 cm, respectively, were found on the extensor aspect of the right upper limb, with irregular margins extending into the normal skin [[Figure 3]]. Clinical and histopathological findings led to the diagnosis of vitiligo with keloid. The patient was treated with NB-UVB for the vitiligo patches and with an intralesional triple medicine combination of triamcinolone acetonide (40 mg/ml), 5-fluorouracil (50 mg/ml), and hyaluronidase (1500 IU) for the keloids. A 40% reduction in the size of keloids and 20% repigmentation of the vitiliginous patches were observed in 3 months.
|Figure 3 Two firm, irregular, erythematous plaques of about 4 cm × 5 cm and 5 cm × 6 cm, respectively, were found on the extensor aspect of the right upper limb, with irregular margins extending into the normal skin|
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| Discussion|| |
Keloids represent benign fibroproliferative tumors originating in response to trauma to the skin. Keloid tissue is characterized by an overabundant accumulation of the extracellular matrix (ECM) components, especially collagen, in the dermis and subcutaneous tissue that extends beyond the confines of the original wound site.
Several theories for the causation of keloid have been proposed, most of which are related to fibroblast dysfunction. Keloid fibroblasts, when compared with fibroblasts isolated from a normal wound, overproduce type I procollagen and express higher levels of certain growth factors such as vascular endothelial growth factor, transforming growth factor β1 and β2, and platelet-derived growth factor.
Individuals with a darker complexion are at an increased risk of developing keloid scarring following trauma and was observed in ∼15–20% of the individuals of Black, Hispanic and Asian ancestry.,
The following phenomena support the relationship between pathological scar formation and skin color:
- The Black population has a higher incidence rate of keloid formation as compared to other races with five to fifteen times higher chances than in the White population;
- Rarity in the development of keloids in patients suffering from albinism or vitiligo;,
- Depending on the number of the melanocytes in various parts of the body, the incidence of pathological scarring can vary in different parts of the body within the same individual; for example, fewer keloids develop over the palm and thenar eminence, where the melanocytes are less common; and
- Individuals who are subjected to increased hormone secretion and skin pigmentation, such as adolescents and pregnant women, are more prone to developing keloids.
All these factors indicate that pathological scarring has a close relationship with melanin pigmentation. Under normal homeostatic conditions, the melanocytes neither proliferate nor express autocrine cytokines. However, during wound healing, they proliferate, and melanin production is activated as a result of the intense inflammation that occurs.
Fibroblasts cocultured with the melanocytes have also been shown to have enhanced type I collagen and TGF-β expression, while the suppressive effects of α-melanocyte-stimulating hormone (αMSH) on collagen production appear to be downregulated in keloids compared to controls.,
Meanwhile, TGF-β has been shown to be one of the most important mediators of fibrosis in keloids. During wound healing, the melanocytes from the basal layer of the epidermis migrate to the damaged area and interact with the proliferative fibroblasts from the dermis, stimulating certain actions that lead to the development of keloids.
Cario-André et al., showed that fibroblasts secrete several active factors that play an essential role in the proliferation of the melanocytes and in the synthesis and degradation of the melanosomes.
Meanwhile, Taylor et al. found that αMSH, produced by the melanocytes in the skin, could activate T cells leading to an increase in the secretion of TGF-β and inhibition in the production of IFN-α, thus stimulating the multiplication of fibroblasts.,To summarize, the number and activity of the melanocytes in the skin can be postulated to play a dominant role in pathological scar formation. This theory is corroborated by the higher incidence rate of keloids in dark-skinned individuals when compared to that in fair-skinned individuals. Furthermore, areas on the body surface containing greater concentrations of the melanocytes are more susceptible to keloid formation than areas with fewer melanocytes. Both of these phenomena can be considered to be related to differences in the number, distribution, and the activity of the melanocytes in the different parts of the body.
Nevertheless, we found three patients in whom keloids had developed on vitiligo patches. Because all keloids were preceded by trauma, it may be hypothesized that the bulbar melanocytes may have suffered injury leading to the bulbar melanocyte–fibroblast interaction and the production of TGF-β1, which leads to keloid formation. However, two out of the three patients showed leucotrichia in the patch where keloid had developed, which suggests that there were no bulbar melanocytes at play at the time of keloid formation. This further suggests that fibroblast proliferation in keloids may not be completely dependent on just stimulation by αMSH secreted by the melanocytes, and that several other pathways may be at play to stimulate the FGF and TGF factors, which are considered central to the development of keloid.
Further, in two of our patients, we observed both a reduction in the size of the keloids as well as the repigmentation of the patches at a shorter span of time on using 5-fluorouracil as a treatment modality, suggesting the use of this drug as a potential therapeutic modality in the treatment of such patients, in whom keloids and vitiligo patches coexist.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]