China
Africa
Explore chapters and articles related to this topic
Disorders of pigmentation
Published in Rashmi Sarkar, Anupam Das, Sumit Sethi, Concise Dermatology, 2021
There are several other types of albinism, most of which are recessive. In the Hermanski–Pudlak syndrome, there is an associated clotting defect due to a platelet abnormality. Patients have a bleeding tendency, interstitial pulmonary fibrosis, and granulomatous colitis. This is ‘tyrosinase positive’ and hair bulbs turn black after they are incubated with l-DOPA. Chediak–Higashi syndrome is characterized by severe immunodeficiency and silvery-white hair, and the histology is classical, showing giant melanosomes within melanocytes. Griscelli syndrome, on the other hand, is a severe immunological disorder with hemophagocytic syndrome in addition to having silvery-white hairs and pigmentary dilution of skin. Waardenburg syndrome is a distinct entity manifesting as achromia of skin, hairs, and eyes, heterochromia iridis, congenital deafness, broad nasal root, and dystopia canthorum. The hallmark finding in piebaldism is white forelock and the presence of normal skin within the depigmented patches.
Differential Diagnosis
Published in Vineet Relhan, Vijay Kumar Garg, Sneha Ghunawat, Khushbu Mahajan, Comprehensive Textbook on Vitiligo, 2020
Hemant Kumar Kar, Gunjan Verma
Vitiligo should be differentiated from Waardenburg syndrome, which is also an autosomal dominant disorder with a similar clinical presentation. It is associated with heterochromia iridis, dystopia canthorum, congenital deafness, and occasionally a congenital megacolon (Hirschsprung disease). Waardenburg syndrome is an expression of a neurocristopathy, involving not only the melanocytes in the skin but also those at the level of the eyes, hair, cochlea, and meninges. Four subtypes have been identified. Piebaldism is comparable to these depigmented macules. However, the predominantly ventral distribution of the lesions, congenital character, stable course, white forelock, and the presence of hyperpigmented maculae within the areas of depigmentation are suggestive for piebaldism [6].
Section 3
Published in Padmanabhan Ramnarayan, MCQs in Paediatrics for the MRCPCH, Part 1, 2017
Retinoblastoma is the most important cause of leucocoria (white reflex), not leucorrhoea! This leads to heterochromia iridis (difference in pupillary colours). 30% have bilateral disease and an autosomally dominantly inherited predisposition, 20% of the unilateral disease have genetic predisposition. The gene is localised to the long arm of chromosome 13. Standard therapy for unilateral disease is enucleation, and bilateral disease is radiotherapy/cryotherapy.
Waardenburg syndrome: characteristics and long-term outcomes of paediatric cochlear implant recipients
Published in Hearing, Balance and Communication, 2019
Pedro Clarós, Agnieszka Remjasz, Astrid Clarós-Pujol, Carmen Pujol, Andrés Clarós
Waardenburg syndrome (WS) is a rare genetic disorder that was first described in 1951 by a Dutch ophthalmologist and geneticist, Waardenburg [1]. It affects one in 40,000 live-born children and is genetically (autosomal dominant) determined [2]. However, there are a few exceptions to this rule. For example, some variants of the WS type II are conditioned by mutations described as 'not fully recessive, not fully dominant' [3]. WS manifests itself in several characteristic features and disorders. Typical features of patients with this syndrome are primarily: hyperplasia of the eyebrows, dystopia canthorum, white forelock, heterochromia iridis and – the most important from the point of view of this publication – variable sensorineural hearing loss (SNHL). There are four types of WS according to the clinical signs. Type 1 includes dystopia canthorum, heterochromia iridis, white forelock, synophrys, hypopigmentation and SNHL (Figure 1). Patients with type 2 have the same characteristics, except dystopia canthorum (Figure 2). Type 3 is also sometimes called Klein-WS and is similar to type 1, but additionally, a contracture of the upper limbs and hypoplastic muscles is diagnosed. WS type 4, also called Shah-WS is characterized by the presence of heterochromia iridis, hypopigmentation, white forelock, synophrys, SNHL and Hirschsprung's disease [2,3].
Iris Juvenile Xanthogranuloma Presenting with Hypopyon
Published in Ocular Immunology and Inflammation, 2022
Mine Esen Baris, Mukaddes Damla Ciftci, Melis Palamar, Suzan Guven Yilmaz
JXG is a rare benign histiocytic proliferation and is regarded as a form of non-Langerhans cell histiocytosis.6 Eye involvement can occur in up to 10% of patients with cutaneous disease, and the iris is the ocular site that is most commonly affected.7 Clinical findings of uveal involvement in JXG may include 1) an asymptomatic localized or diffuse iris tumor, 2) unilateral glaucoma, 3) spontaneous hyphema, 4) a red eye with signs of uveitis, or 5) congenital or acquired heterochromia iridis.4 In a study of 30 patients with JXG involving the eye and ocular adnexa, Samara et al.5 reported that the most common site of involvement was the iris (68%) while the mean age at presentation of iris JXG was 3.3 years. In the current case, the baby was only 45 days old suggesting that even younger children can be affected. Presenting signs in patients with iris JXG were reported as hyphema (38%), iritis (43%), heterochromia (%29), and iris neovascularization (%29).5 In the current case, the presenting sign was hypopyon, which is rare. Even though JXG has been reported to be associated with acute or chronic anterior uveitis, to the best of our knowledge, this is the first case in the literature in which hypopyon was the presenting sign. It is also possible that the observed hypopyon was in reality a resolving hyphema. As we were unable to take a sample, de-hemoglobinized hemorrhage cannot be excluded completely; nonetheless, the clinical presentation and the infant’s medical history, as narrated by the mother, indicated a hypopyon. Hypopyon in an infant requires a careful investigation for a large group of diseases such as retinoblastoma, leukemia and medulloepithelioma, among others. The underlying cause might even be trauma if a penetrating injury occurred.8