Annular Epidermolytic Ichthyosis
|Disease group||Keratinization disorders|
|DISEASE NAME||ANNULAR EPIDERMOLYTIC ICHTHYOSIS|
|Synonymous||Cyclic Ichthyosis with Epidermolytic Hyperkeratosis|
|Estimated prevalence||< 1 / 1 000 000|
|Gene (s)||KRT1 (139350), KRT10 (148040)|
In a consensus conference in 2009, a new classification system and terminology has been established for ichthyoses . Ichthyoses are determined as Mendelian disorders of cornification (MeDOC) that are characterized by universal scaling of the skin. In two main categories, non-syndromic forms (phenotype restricted to the skin) are distinguished from syndromic forms (involvement of other organs). A further distinction is made between common and rare forms. Within the non-syndromic forms the term keratinopathic ichthyosis is used as an umbrella term to describe all forms of ichthyosis that are based on mutations in keratin genes. The keratinopathic ichthyoses manifest at birth and sometimes involve blistering [2, 3].
Annular epidermolytic ichthyosis (AEI) is a rare clinical variant of epidermolytic ichthyosis (EI) characterized by the presence of a blistering phenotype at birth and the development from early infancy of annular polycyclic erythematous scales on the trunk and extremities .
At birth, clinical features are similar to those of classical EI with erythroderma, blistering and superficial skin erosions at sites of minor trauma. In contrast to EI, an improvement of clinical symptoms occurs during early infancy after which patients develop outbursts of annular polycyclic erythematous scales on the trunk and extremities. Skin is normal between the outbursts. These skin abnormalities persist for several weeks to several months with only benign localized disease observed in adulthood. Patients also present palmoplantar hyperkeratosis .
The disease is caused by mutations in the KRT1 (12q13.13) and KRT10 (17q21.2) genes, encoding keratins 1 and 10 respectively. These mutations impair keratin filament formation and weaken the structural stability of the keratinocyte cytoskeleton .
The features that distinguish AEI from EI are dramatic episodic flares of annular, polycyclic erythematous plaques with scale, which coalesce to involve most of the body surface and can persist for several weeks or even months .
Treatment options include topical and oral retinoids, topical glucocorticoids, calcipotriene, and keratolytics [6, 7].
Oji V, Tadini G, Akiyama M, Blanchet Bardon C, Bodemer C, Bourrat E, Coudiere P, DiGiovanna JJ, Elias P, Fischer J, Fleckman P, Gina M, Harper J, Hashimoto T, Hausser I, Hennies HC, Hohl D, Hovnanian A, Ishida-Yamamoto A, Jacyk WK, Leachman S, Leigh I, Mazereeuw-Hautier J, Milstone L, Morice-Picard F, Paller AS, Richard G, Schmuth M, Shimizu H, Sprecher E, Van Steensel M, Taïeb A, Toro JR, Vabres P, Vahlquist A, Williams M, Traupe H. (2010) Revised nomenclature and classification of inherited ichthyoses: results of the First Ichthyosis Consensus Conference in Sorèze 2009. J Am Acad Dermatol 63:607-641.
Schmuth M, Martinz V, Janecke AR, Fauth C, Schossig A, Zschocke J, Gruber R. (2013) Inherited ichthyoses/generalized Mendelian disorders of cornification. Eur J Hum Genet 21:123-133.
Traupe H, Fischer J, Oji V. (2013) Nonsyndromic types of ichthyoses – an update. J Dtsch Dermatol Ges Oct 11. doi: 10.1111/ddg.12229. [Epub ahead of print]
Information retrieved from Orphanet: http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=281139 Dr Nathalie JONCA, Pr Juliette MAZEREEUW-HAUTIER. Last update: December 2012.
Sybert VP, Francis JS, Corden LD, Smith LT, Weaver M, Stephens K, McLean WHI. (1999) Cyclic ichthyosis with epidermolytic hyperkeratosis: a phenotype conferred by mutations in the 2B domain of keratin K1. Am J Hum Genet 64: 732-738.
Sahn EE, Weimer CE Jr, Garen PD. (1992) Annular epidermolytic ichthyosis: A unique phenotype. J Am Acad Dermatol 27:348-355.
Michael EJ, Schneiderman P, Grossman ME, Christiano AM. (1999) Epidermolytic hyperkeratosis with polycyclic psoriasiform plaques resulting from a mutation in the keratin 1 gene. Exp Dermatol 8:501-503.