How to Treat PULL-OUT SECTION www.australiandoctor.com.au COMPLETE HOW TO TREAT QUIZZES ONLINE www.australiandoctor.com.au/cpd to earn CPD or PDP points. INSIDE General approach Vitiligo Infective causes Other acquired disorders Genetic and congenital disorders THE AUTHORS DR DEEPANI RATHNAYAKE consultant dermatologist, Base Hospital Dambulla, Sri Lanka. Background DISORDERS of pigmentation are Disorders of PROFESSOR ROD SINCLAIR a common presentation in derma- director and head, dermatology, tology and general practice. Part 1 Epworth Hospital, Melbourne, of this update on disorders of pig- Victoria. mentation outlined the physiology of skin pigmentation and the path- pigmentation ological mechanisms that lead to these disorders. It then discussed the general approach to pigmentary dis- orders and focused on the diagnosis — Part 2: and management of hyperpigmen- tary disorders. Hypopigmentation, like hyper- pigmentation, can lead to signifi- cant psychosocial problems. It can Hypopigmentation even be a reason for social rejec- tion. This is especially pertinent in the cosmetic management of the This is the second of a two-part series on disorders of pigmentation. Part 2 covers hypopigmentary hypopigmented lesions that can be disorders in detail. significantly disfiguring on the face and other exposed skin. Acquired hypopigmentation may be associ- ated with an underlying systemic disorder that may be treatable. The search and treatment for underlying Copyright © 2014 conditions are just as important as Australian Doctor All rights reserved. No part of this the management of the presenting publication may be reproduced, cosmetic complaint. distributed, or transmitted in any This article discusses the general form or by any means without approach to hypopigmented skin the prior written permission of the publisher. lesions and then specific hypopig- For permission requests, email: mentary conditions in more detail. [email protected] cont’d next page www.australiandoctor.com.au 18 April 2014 | Australian Doctor | 23 How To Treat – Disorders of pigmentation— Part 2: Hypopigmentation General approach HYPOPIGMENTARY disorders The use of a Figure 1: may be due to both genetic and Hypopigmentation acquired causes. The pathogenic Wood’s lamp can in a patient with mechanisms by which hypopig- considerably improve systemic sclerosis mentation occurs can be broadly on the extensor divided into two processes: the diagnosis of surface of the right • Reduced or absent melanocytes; hypopigmentary elbow. or • Reduced number of melano- lesions, especially in somes and melanin in the skin patients with lighter (table 1). skin colour. Diagnosis Most hypopigmentary disorders can be diagnosed with a detailed history and examination. A hypo- pigmented lesion present at birth may be a naevus or an ash-leaf macule. A history of a preceding Wood’s lamp examination on skin rash favours the diagnosis of Table 1: Pathogenic mechanism in hypopigmentary disorders hypopigmented lesions are shown post-inflammatory hypopigmenta- Disease Defect in the table below left. tion. The presence of anaesthesia in a hypopigmented lesion is an Piebaldism Congenital absence of melanocytes General principles of important clue in a clinical diagno- Vitiligo, discoid lupus erythematosus, Acquired destruction of melanocytes management sis of leprosy. Additional investiga- systemic sclerosis (figure 1) Cosmetic camouflage is an import- tions are necessary if the diagnosis ant part of managing hypopig- cannot be confirmed on clinical Albinism, phenylketonuria, drugs (eg, Reduced melanin production mented skin lesions. grounds alone. A skin biopsy will skin-whitening creams) It is important to emphasise be useful in some patients. to the patient that, somewhat Tuberous sclerosis Reduced melanosome transfer to Idiopathic guttate hypomelanosis counter-intuitively, tanning wors- keratinocytes is often misdiagnosed and treated as ens the cosmetic appearance of pityriasis versicolor. The distinction Post inflammatory hypopigmentation Increased melanin and keratinocyte hypopigmented lesions on fair or may be better elucidated by taking due to psoriasis turnover light skin. It makes the contrast scrapings from the skin lesions in between normal and depigmented question. Scrapings from a lesion of Table 2: Wood’s lamp features in hypopigmentary disorders skin more noticeable. pityriasis versicolor typically have a Furthermore, depigmented skin ‘spaghetti and meatballs’ appearance Hypopigmentary disorder Features under Wood’s lamp has a higher risk for chronic sun under the microscope after dissolv- Pityriasis versicolor Yellow to yellow-green fluorescence damage and skin cancer. This risk ing in 30% potassium hydroxide on of sun damage is heightened in a Vitiligo Bright areas with sharp borders varying in a glass slide. country such as Australia where location and extent As mentioned in Part 1, the use there are long hours of intense of a Wood’s lamp can consider- Tuberous sclerosis Patches; characteristic ash-leaf shape sun. A broad-spectrum sunscreen ably improve the diagnosis of Hypomelanosis of Ito Whorled or streaked patterns. with both UVB and UVA protec- hypopigmentary lesions, especially Naevus anaemicus Lesion becomes inapparent tion helps resist tanning with addi- in patients with lighter skin colour tional protection against chronic (table 2). The features found under Hypochromic naevi Off-white accentuation sun damage. Vitiligo VITILIGO is an acquired pig- Table 3: Classification of hypopigmentation/depigmentation mentary disorder of the skin and disorders — genetic causes mucous membranes presenting with well-demarcated depig- Extent of disorder Possible causes mented macules of varying sizes Localised Piebaldism and shapes. Depending on the Waardenburg syndrome clinical presentation and dis- Ziprkowski–Margolis syndrome tribution, vitiligo can be classi- Hypomelanosis of Ito and mosaicism fied as localised or generalised. Focal dermal hypoplasia Localised disease can be further Naevus depigmentosus classified as focal (one or more Tuberous sclerosis complex macules), segmental (macules in Incontinentia pigmenti a dermatomal distribution) and Generalised Albinism mucosal (mucous membranes Albinoid disorders (Chédiak–Higashi syndrome, alone). Generalised vitiligo can Griscelli syndrome, Prader–Willi syndrome, be acrofacial (distal fingers and phenylketonuria, homocystinuria) periorificial areas), vulgaris (scattered widely distributed for (tables 3 and 4). For example: be unsatisfactory. Complete patches) or mixed. Universal • Pityriasis alba has an ill-defined repigmentation is unlikely in vitiligo refers to extensive and border with slight scaling, usu- most patients and recurrences almost complete depigmentation ally seen on the face in children. are common. Treatment should of the whole body. • Pityriasis versicolor has coalesc- depend on the individual. Patients ing macules with slight scaling. It should be properly counselled Pathogenesis Figure 2: Large anaesthetic hypopigmented macular lesion with raised borders is seen as yellow to yellow-green about the treatment outcome and There are several theories for the due to leprosy. under a Wood’s lamp. side effects. Cosmetic disfigure- pathogenesis of vitiligo. Genetic • Hypopigmented mycosis fun- ment is the main reason for treat- factors may play a role and a posi- anocyte destruction. Vitiligo may vitiligo a mixture of complete and goides has skin atrophy and ill- ment especially in darker skin tive family history is seen in some be associated with other autoim- partial pigmentary loss can be defined lesions. types. Non-treatment is an option patients. There is an absence of mune disorders. seen. There may be associated leu- • Lichen sclerosus et atrophicus in skin type 1 and 2. melanocytes in the lesions, which kotrichia. The lesions may appear has guttate hypopigmentation Topical therapies are suitable is due to the destruction of mel- Diagnosis at sites of trauma from Koebner’s with skin sclerosis. for patients with few lesions. anocytes. Autoimmune mecha- Vitiligo is a clinical diagnosis. phenomenon and this usually indi- • Leprosy has features of anaes- Topical steroid preparations are nisms, cytotoxic mechanisms, Patients may present with progress- cates an active disease. thesia, and has raised borders commonly used as first-line ther- intrinsic defect of melanocytes, ive depigmentation of the skin. The Differentiating vitiligo from (figure 2). apy in localised vitiligo. They oxidant-antioxidant mecha- rate of progression is variable. Usu- other hypopigmented lesions can are moderately successful, but nisms, and neural mechanisms are ally there is complete depigmenta- be difficult sometimes and certain Treatment long-term application can cause thought to contribute to the mel- tion in the lesions but in trichrome specific features should be looked Treatment of vitiligo can often cont’d page 26 24 | Australian Doctor | 18 April 2014 www.australiandoctor.com.au How To Treat – Disorders of pigmentation— Part 2: Hypopigmentation from page 24 Table 4: Classification of hypopigmentation/depigmentation Figure 3: skin atrophy. Topical tacroli- disorders — acquired causes Multiple small mus ointment (0.03% or 0.1%) depigmented Type of Acquired causes is an effective alternative, partic- lesions on the ularly when the disease involves disorder trunk after the head and neck. It can also be Autoimmune Vitiligo, Vogt–Kayonagi syndrome, systemic sclerosis, resolution of the combined with laser and photo- discoid