Research for medical professionals
From Dalian China, comes some interesting research on the epidermis (the uppermost layer of the skin, where the pigment cells reside) in vitiligo. Dr Lui and colleagues (Skin Pharmacol Physiol. 2010; 23: 193-200) noted that studies have demonstrated that alterations in skin biophysical properties in vitiligo have not yet been well defined. In their study, stratum corneum (SC) hydration, the skin surface acidity and epidermal permeability barrier function in vitiligo were evaluated.
They found that in addition to SC hydration, both melanin and erythema index were significantly lower in vitiligo skin than in nonlesional sites, while no difference in skin surface acidity between vitiligo-involved and uninvolved areas was observed. In addition, the SC integrity in the involved areas was similar to that in the uninvolved areas. However, barrier recovery in vitiligo-involved sites was significantly delayed in comparison with uninvolved sites.
The research group of Professor Richard Spritz in the University of Colorado USA has undertaken many important studies of the genetic basis of vitiligo over the last few years. In the most recent paper (Nature Genetics 2012; 44: 676-80) they summarize that most genes that indicate a susceptibility to vitiligo are involved with proteins or parts of the pigment cell that are important for the functioning of the immune system.
Dr van Geel and researchers have looked at how halo naevi ( a common mole with a white ring around, showing the sort of pigment loss that is seen in vitiligo) can present together with vitiligo or separately (Br J Dermatol 2011; 164: 743-9). Their results support the theory that halo naevi can represent a distinct condition but in a subset of patients, the occurrence of halo naevi may be an initiating factor in the pathogenesis of vitiligo.
Dr N van Geel and colleagues of Ghent has looked at the Koebner phenomenon (KP), the occurrence of the development of vitiligo within an area of skin that has been damaged by localized often mild trauma (Br J Dermatol 2012;167:1017-24.). They developed a new assessment method for KP, taking into account both history and clinical examination, which seems to be a useful and valuable tool for assessing KP in daily practice. The results support the hypothesis that KP may be used to assess and predict the course of vitiligo
The pathogenesis of vitiligo is believed to involve oxidative stress (an imbalance between the presence of toxic so-called reactive oxygen species (ROS) and the body’s ability to detoxify them). Based on this, according to Dell Anna and colleagues in Rome, Italy, the generation of reactive oxygen species (ROS) by the mitochondria within melanocytes and blood cells may be relevant in the pathogenesis of vitiligo (J Cell Physiol 2010; 223: 187-93).
These authors suggest that the modification of membrane lipid components in vitiligo cells may be a biochemical basis for the mitochondrial impairment and the subsequent production of intracellular ROS following the exposure to a mild stress.
Although the exact cause of vitiligo remains obscure, evidence suggests that autoimmunity plays a role in the pathogenesis of the disease. Previously, tyrosine hydroxylase (important in the production of melanin pigment) was identified as a autoantigen target in vitiligo. Researchers at the University of Sheffield have found that tyrosine hydroxylase is an antibody target in non-segmental vitiligo (antibodies found in 23%) but not in segmental type and that tyrosine hydroxylase antibodies appear to be more frequent in patients with active vitiligo (Kemp et al. Exper Dermatol 2011; 20: 35-40).
Laser treatment research
Patients often wonder whether lasers (other than the Excimer) will help their vitiligo. Some lasers can help with depigmentation, on the rare occasions when this is indicated. Hossani-Madani et al (of Washington DC, USA) have shown that the Q-switched ruby laser does seem to have the advantage of inducing depigmentation more quickly than the usual topical depigmentation treatment of monobenzyl ether of hydroquinone, but with more discomfort (G Ital Dermatol Venereol. 2011; 146: 373-95).
Quality of life and psychological aspects
Dr Kiprono and colleagues from Tanzania found that in vitiligo patients of African descent there was a moderate impairment of quality of life when studied using the Dermatology Life Quality Index (DLQI: Int J Dermatol. 2013; 52: 191-4). In Turkey Dr Bilgic and colleagues looked at depression in children and adolescents with vitiligo (Clin Exper Dermatol 2011; 36: 360-5).
They found that vitiligo relates to the severity of depression in children, but a similar effect was not observed in adolescents, and suggested that the location of the lesions is a significant factor that leads to quality of life impairment, possibly because of its effects on identity development. In Korean adolescents with vitiligo, researchers found that quality of life is closely related to the patients’ apprehensions about their disease, psychosocial adjustment, and psychiatric morbidity, rather than the clinical severity of the condition itself (Choi et al. J Eur Acad Dermatol Venereol 2010; 24: 524-9).
The ways in which British Asian women manage and adjust psychosocially to vitiligo, and the potential role of ethnicity and culture in this process have been investigated (Thompson et al. Br J Dermatol 2010; 163: 481-6). Asian women described feeling visibly different and all had experienced stigmatization to some extent. Avoidance and concealment were commonplace. Experiences of stigmatization were often perceived to be associated with cultural values related to appearance, status, and myths linked to the cause of the condition.
Researchers from Belgium found that the quality of life impairment in women affected with vitiligo assessed using the DLQI, was equal to the impairment caused by psoriasis (Ongenae et al. Br J Dermatol 2005; 152: 1165-72). Sukan and Maner researching in Turkey, found that vitiligo had a negative impact on the sex lives of women with vitiligo (J Sex Marital Ther. 2007; 33: 55-64.).
Dr van Geel and collaborators have also looked at segmental vitiligo, which is characterized by a unilateral and localized distribution (Br J Dermatol. 2013; 168: 56-64). So far, the underlying mechanism is still an enigma. In order to obtain an insight into the aetiopathogenesis of segmental vitiligo the researchers compared its distribution pattern with those of dermatoses with a possible mosaic or neurogenic background.
The results showed that the distribution pattern of segmental vitiligo is not entirely similar to any other skin disease, although some mosaic skin disorders have more overlap with segmental vitiligo than others. Dr van Geel and colleagues concluded that cutaneous mosaicism may be involved in segmental vitiligo. Mosaicism is a condition in which cells within the same person have a different genetic makeup. Experts have looked at how vitiligo is classified (Ezzedine et al. Pigment Cell Melanoma Res. 2012; 25: E1-13). They concluded that segmental vitiligo be classified separately from all other forms of vitiligo and that the term ‘vitiligo’ be used as an umbrella term for all non-segmental forms of vitiligo, including ‘mixed vitiligo’ in which segmental and non-segmental vitiligo are combined and which is considered a subgroup of vitiligo. The experts recommended that disease stability be best assessed based on the stability of individual lesions rather than the overall stability of the disease as the latter is difficult to define.
With regard to the surgical treatment of vitiligo, Shane and colleagues from India write in the journal Dermatologic Surgery (2011; 37: 176-82) that the results of non-cultured pigment cell (melanocyte) transplantation (taken from the patient’s own normally pigmented skin) can be improved by suspending the melanocytes in the patients’ own serum: this could be an important innovation in the surgical management of patients with stable vitiligo.
Dr Mulekar and colleagues assessed the efficacy of the ReCell kit (Clinical Cell Culture, Cambridge, U.K.) and to compare it with conventional melanocyte-keratinocyte transplantation (MKT) for the treatment of vitiligo (Br J Dermatol 2008; 158: 45-9) and found of the five lesions treated with ReCell two lesions showed 100%, one 65% and one 40% repigmentation, and one lesion failed to repigment, whereas of the five lesions treated by conventional MKT three showed 100% and one 30% repigmentation and one failed to repigment (ReCell is not generally available in the UK).
It is difficult to find a systemic treatment for vitiligo at the moment. Dr Szczurko et al have looked at ginkgo biloba (BMC Complement Altern Med. 2011 Mar 15;11:21). Twelve participants 12 to 35 years old were recruited to a prospective open-label pilot trial and treated with 60 mg of standardized Ginkgo biloba two times per day for 12 weeks. Effectiveness was assessed using the Vitiligo Area Scoring Index (VASI) and the Vitiligo European Task Force (VETF), which are validated outcome measures evaluating the area and intensity of depigmentation of vitiligo lesions.
Ingestion of 60 mg of Ginkgo biloba BID was associated with a significant improvement in total VASI vitiligo measures and VETF score spread, and a trend towards improvement on VETF measures of vitiligo lesion area and staging. However, proper clinical trials are needed before this can be generally recommended as a treatment.
Piperine, derived from black pepper, has been mooted as a potential treatment for vitiligo. So far there have only been studies in animals, which have shown an increase in pigmentation in mice treated with a piperine derivative (Faas et al. Br J Dermatol 2008; 158: 941-50). With regard to cosmetic camouflage treatment, Tanioka and colleagues from Kyoto Japan discovered that this improves quality of life (J Cosmet Dermatol 2010; 9: 72-5). New European guidelines have been introduced (see Taieb et al. Br J Dermatol. 2013; 168: 5-19).
Topical and ultraviolet treatments
Topical treatments are the usual place to start with treatments for vitiligo, though it does depend on the site and extent of involvement. Bhuvana et al (Indian J Dermatol 2001; 56: 445-6) suggest that topical tacrolimus is effective for localized vitiligo. Eryilmaz and colleagues find that the other topical immunomodulator, pimecrolimus, might be useful (J Eur Acad Dermatol Venereol 2009; 23: 1347-8). Both of these approaches have been mentioned in already published guidelines.
The use of targeted narrow-band ultraviolet B (UVB) usually in the form of the Excimer, advocated by Le Duff et al (Br J Dermatol 2010; 163: 188-92) is now well known for treating localized vitiligo, though this therapy is not available to most dermatologists in the UK.
Vitiligo and skin cancer
The risk of skin cancer in patients with vitiligo might be thought of as increased since there is a tendency to burn when in the sun. The matter has been investigated by a team from The Netherlands (Teulings et al. Br J Dermatol 2013; 168: 162-71). They conducted a survey designed to assess lifetime prevalences of malignant melanoma and non-melanoma skin cancer (NMSC) in patients with vitiligo compared with non-vitiligo controls.
Their findings suggest that patients with vitiligo have a threefold lower probability of developing malignant melanoma and NMSC. The reasons for this have yet to be fully understood. Hear about this on BBC iPlayer: CLICK HERE
Vitiligo and thyroid disease
Clinically, dermatologists have noted for some years an association between vitiligo and thyroid disease. Vrijman and colleagues from Amsterdam, The Netherlands, undertook a review of this (Br J Dermatol 2012; 167: 1224-35) and found that there was indeed an association. They discovered the frequency of thyroid disease in vitiligo patients was 15.1% , autoimmune thyroid disease 14.3% and the presence of thyroid-specific autoantibodies 20Â·8%. All patients with vitiligo should have their thyroid function checked.