Volume 1 • Issue 6 • 1000150 Pigmentary Disorders ISSN: 2376-0427, JPD, hybrid open access journal Bulat et al., Pigmentary Disorders 2014, 1:6 DOI: 10.4172/2376-0427.1000150 Review Article Open Access Idiopathic Guttate Hypomelanosis: A Comprehensive Overview Vedrana Bulat 1 , Mirna Šitum 1 , Goran Maričić 2 , Vesna Lukinović Škudar 3 , Maja Kovačević 4 *, Lada Bradić 4 , Josip Ježovita 5 and Andrija Stanimirović 6 1 Department of Dermatology and Venereology, University Hospital Center “Sestre milosrdnice”, Vinogradska cesta 29, Zagreb, Croatia 2 Naftalan Special Hospital for Medical Rehabilitation, Omladinska 23a, Ivanić Grad, Croatia 3 Medical University Zagreb, Šalata 3, Zagreb, Croatia 4 University Hospital Center “Zagreb“, Kišpatićeva 12, Zagreb, Croatia 5 Centre for Croatian Studies, University of Zagreb, Borongajska cesta 83d, Zagreb, Croatia 6 Department of Clinical Medicine, University of Applied Health Sciences, Mlinarska 38, Zagreb, Croatia *Corresponding author: Maja Kovačević, University Hospital Center “Zagreb“, Kišpatićeva 12, Zagreb, Croatia, Tel: 38513820077; E-mail: kovacevic.maja01@ gmail.com Received: November 07, 2014; Accepted: November 12, 2014; Published: November 15, 2014 Citation: Bulat V, Šitum M, Maričić G, Škudar VL, Kovačević M, et al. (2014) Idiopathic Guttate Hypomelanosis: A Comprehensive Overview. Pigmentary Disorders 1:150. doi: 10.4172/2376-0427.1000150 Copyright: © 2014 Bulat V, et al. The terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Keywords: Hypomelanosis; Melanocytes; Hypopigmentation; Introduction Hypomelanosis denotes an absence or reduction of melanin in the tissues, especially in the skin. Idiopathic Guttate Hypomelanosis (IGH), synonym hypomelanosis of Cummins and Cottel, is considered melanopenic hypomelanosis that may result from numerous and complex pathologic mechanisms. IGH does not appear to result from a reduction in the number of epidermal and/or follicular melanocytes, but rather from an impaired synthesis of melanin, decreased size and poor melanization of melanosomes and inadequate transfer of melanosomes from melanocytes to surrounding keratinocytes. Te result of this process is rapid elimination of inactive melanocytes (Figure 1) [1,2]. IGH is a very common, acquired and frequently ignored condition. A positive correlation has been established between the incidence of this condition and aging. It is seen in up to 80% of individuals over the age of 70 years. Te basic defect in IGH melanocytes may refect the aging process [1]. Te precise etiology of IGH is unknown, but a history of excessive, chronic sun exposure probably also plays a role for IGH is rarely seen in West Indians raised in England, but is common in those who spent their childhood in the Caribbean. According to Flabella et al. genetic infuences have also been proposed as possible causes due to higher prevalence of IGH in the family of patients with IGH than in the control group [3]. IGH occurs in all races and skin types with a frequency ranging from 46 to 70%. However, it is more striking in darker-skinned racial/ ethnic groups. In Caucasians, it may favour those with brown eyes and brown hair. An apparent female predominance is probably the result of heightened perception of a cosmetic problem. Clinical Features Multiple, well-circumscribed, asymptomatic, polygonal, white macules are symmetrically distributed on sun-exposed areas (Figures 2-5). Skin lesions are most commonly seen on the extensor forearms and shins; the remainder of the extremities can be afected, but rarely the face (Figure 6). Te lesions range usually from 2 to 8 mm in diameter and ofen delineated by the skin furrows, with occasional larger lesions up to 2.5 cm. Once present, they do not increase in size with time and do not coalesce. Te number of lesions increases with age. Hypomelanosis is an abnormality solely in the colour of the skin, with no texture abnormality. No spontaneous repigmentation has been observed. Vellus hairs within the lesions usually retain their pigment. Patients have usually signs of photoaging, including lentigines, and xerosis in the same involved areas [3]. Diagnosis IGH is usually diagnosed clinically following a complete history and physical examination. Patients with IGH should be examined under both visible and ultraviolet light of about 365 nm wavelengths (i.e. Wood`s lamp). While under visible light, the contrast between hypomelanosis and surrounding skin is not striking in light-skinned individuals, with Wood`s lamp examination more lesions may become apparent and a decrease in pigment is confrmed. Skin biopsy is not usually needed. Histologic examination of involved skin is usually most helpful for postinfammatory hypomelanosis such as sarcoidosis and mycosis fungoides, whereas in others (e.g. pityriasis lichenoides chronica) the histologic fndings are ofen nonspecifc [4]. Histologic Features Te most prominent histologic features of IGH are a fattening of the dermal-epidermal junction, moderate to marked reduction or focal absence of melanin granules in the basal and suprabasal layers, and a basket-weave hyperkeratosis [5,6]. Immunohistochemical stains such as HMB45, Mel-5 or S100 reveal a moderate to relatively marked reduction of DOPA-positive epidermal Abstract Idiopathic guttate hypomelanosis (IGH) is a very common, acquired, and frequently ignored condition characterized by an appearance of multiple, well-circumscribed, asymptomatic, polygonal, white macules symmetrically distributed on the extensor forearms and shins. Once present, skin lesions do not increase in size with time and do not coalesce. IGH occurs in all races and skin types, especially in elderly patients over the age of 70 years. IGH appears to result from an impaired synthesis of melanin, decreased size and poor melanization of melanosomes and inadequate transfer of melanosomes from melanocytes to surrounding keratinocytes. The diagnosis of IGH is usually made clinically. Despite straightforward clinical appearance of IGH in majority of cases, several additional diagnostic procedures may be needed for confrmation of diagnosis in some less clear cases. J o u r n a l o f P i g m e n t a r y D i s o r d e r s World Health Academy ISSN: 2376-0427 Journal of Pigmentary Disorders