8 - 47 - ICHTHYOSIS Flashcards
hallmark of ichthyosis
scale
reflects altered differentiation of the epidermis
A rare autosomal dominant genodermatosis. Patients are born with redness and blistering. The redness subsides over the subsequent weeks to months, and the skin develops corrugated hyperkeratosis, particularly over flexural areas (Fig. 47-18).
Superficial Epidermolytic Ichthyosis
In netherton syndrome, hair from multiple areas should be examined because only 20% to 50% of hair may be affected; the characteristic abnormality may be more commonly observed on _______
eyebrow hair
The hair defects may not be detectable at birth and may disappear with age
Clinical features of LAMELLAR ICHTHYOSIS PHENOTYPE of autosomal recessive congenital ichthyosis (ARCI)
The LI phenotype of ARCI is apparent at birth, and the newborn usually presents encased in a collodion membrane (see Fig. 47-3). At this time, the skin may be red. Over time, the skin develops large, platelike scales, and most are centrally attached with raised borders. The scales tend to be largest over the lower extremities, where the large, platelike scales separated by superficial fissuring can lead to an appearance similar to that of a dry riverbed. During childhood and into adulthood, the degree of erythema may vary. Involvement of the palms and soles in LI is variable and ranges from minimal hyperlinearity to severe keratoderma.
Progressive corneal opacification; either mild generalized hyperkeratosis or discrete erythematous plaques, which may be symmetric; neurosensory deafness
Keratitis-Ichthyosis-Deafness (KID) Syndrome; recessive has been reported
Non-syndromic forms of Ichthyoses
Ichthyosis vulgaris (IV)
Recessive X-linked Ichthyosis (RXLI)
Keratinopathic Ichthyosis (KI)
Autosomal Recessive Congenital Ichthyosis (ARCI)
Presents with congenital erythroderma, malformation of the auricle, and tapering of the digits which leads to the frequent clinical diagnosis of CIE.
In childhood, palmoplantar keratoderma develops, and the severity ranges from mild to severe.
Most individuals develop small islands of normal-appearing skin beginning in childhood (Fig. 47-20), although later presentation has also been reported.
ICHTHYOSIS WITH CONFETTI
Heterogeneous; may have verrucous, firm, hyperkeratotic (hystrix) spines, often linearly arrayed in flexural creases; blisters; may have erythroderma and/or palmar/plantar keratoderma
Epidermolytic Ichthyosis
mutation in TGM1 gene
ARCI Lamellar Ichthyosis
An autosomal recessive disorder characterized by accumulation of triglycerides in the cytoplasm of keratinocytes, leukocytes, muscle, liver, fibroblasts, and other tissues with normal blood lipid levels
An autosomal recessive disorder that includes a broad spectrum of clinical phenotypes linked by the characteristic features of **sulfur deficient, brittle hair **that exhibits alternating birefringence (tiger tail banding) when viewed under polarizing microscopy (Fig. 47-26).
Associated with Trichorrhexis Invaginata
Netherton Syndrome
mutated gene in Epidermolytic ichthyosis
KRT1, KRT10
Protein: Keratin 1 or 10
Large, platelike, brown scale over most of the body; accentuated on lower extremities; ectropion, eclabium, and alopecia. palmar/ plantar involvement varies
AUTOSOMAL RECESSIVE CONGENITAL ICHTHYOSIS (ARCI); LAMELLAR ICHTHYOSIS
Differentiate Lamellar ichtyosis from Congenital Ichthyosiform Erythroderma (CIE)
In LI , one sees large, dark, platelike scales, and although infants may be red at birth, adults have little to no erythroderma (Figs. 47-4 to 47-6). In the more severe, classic presentation of LI, tautness of the facial skin leads to traction on the eyelids and lips, resulting in ectropion and eclabium. Scarring alopecia, most prominent at the periphery of the scalp, may be partly caused by traction at the hairline.
In contrast Congenital Ichthyosiform Erythroderma, has generalized redness and fine, white scales (eg, Figs. 47-7 and 47-9). Patients with classic CIE have little to no ectropion, eclabium, or alopecia.
Mutations in SPINK5, encoding a serine protease inhibitor, cause ________ and confirm a role for proteolysis and protease inhibitors in normal epidermal differentiation.
Netherton Syndrome
ABCA12 gene mutation
Harlequin Ichtyosis
Multiple Sulfatase Deficiency
Generalized fine to coarse hyperkeratosis; spastic diplegia; mental retardation; retinal glistening white dots
Sjögren-Larsson syndrome
Markedly thickened skin with geometric, deep fissures; at birth survivors develop severe erythroderma
Harlequin Ichthyosis
most common malignancy reported with acquired ichthyosis
Hodgkin Disease
thickening of the skin with or without visible scale known as ___________
Keratoderma
present with “tiger tail hair”
Mutations in the gene encoding transglutaminase-1 , an enzyme that catalyzes the cross-linking of proteins and attachment of ceramides during the formation of corneocytes, are found in a large fraction of patients with ________________
Autosomal Recessive Congenital Ichthyosis (ARCI)
A _________ is born encased in a translucent, parchment-like membrane that is taut and may impair respiration and sucking.
Collodion
most common skin finding of Trichothiodystrophy
A survey of 112 cases reported in the literature found ichthyosis (65%) as the most common skin finding followed by photosensitivity (42%)
what is elevated in the plasma of patients with REFSUM DISEASE
2 diseases that should be considered in patients with atopy that is resistant to usual treatment
(this is from Dr. Montenegro)
Netherton Syndrome
Hyper-IgE Syndrome
subtype of LI in which affected individuals develop the scaling typical of LI but limited to the bathing suit area
Bathing Suit Ichthyosis
The distribution correlates with warmer areas of skin. Decreased transglutaminase is found in these areas, and unique, temperature-sensitive mutations in TGM1 have been identified in affected individuals.
Erythematous, scaly plaques, symmetrically distributed over extremities, buttocks, and face; stabilize in early childhood; trunk tends to be spared
Progressive symmetric erythrokeratoderma
HYSTRIX (verrucous, firm, hyperkeratotic) SPINES may be seen in
Epidermolytic Ichthyosis
Ichthyosis vulgaris (FLG mutation). Small, centrally adherent scales generally spare intertriginous areas. Increased number and depth of palmar markings are usually noted.
may present with “Scissor Gait” (may be due to spastic diplegia)
(this is from Dr. Montenegro. not in FItz)
comma-shaped corneal opacities
X-linked Recessive Ichthyosis
Clinical features of Ichthyosis vulgaris
- The scale of IV is usually most prominent on the extensor surfaces of the extremities, with flexural sparing.
- The diaper area tends to be spared.
- There may be fine, white scales over large areas. Particularly on the lower extremities which are often the most severely involved area, the scales may be centrally attached, with “cracking” (superficial fissuring through the stratum corneum) at the edges.
Chanarin-Dorfman Syndrome (Neutral Lipid Storage Disease)
Non-syndromic forms of Ichthyoses
Ichthyosis vulgaris (IV)
Recessive X-linked Ichthyosis (RXLI)
Keratinopathic Ichthyosis (KI)
Autosomal Recessive Congenital Ichthyosis (ARCI)
Figure 47-15 Epidermolytic ichthyosis infantile presentation. A, Newborn showing blistering and erosions. B, Epidermolytic ichthyosis histology. The stratum corneum is thickened (hyperkeratosis), and there is prominent vacuolar degeneration of suprabasilar epidermis most marked at the granular layer.
Generalized hyperkeratosis and figurate, migratory red patches
Trichothiodystrophy
Mutations in FLG result in reduced or absent filaggrin and decreased moisture binding in the stratum corneum of patients with _____________
Ichthyosis Vulgaris
gene mutated in Erythrokeratodermia variabilis, Generalized type
GJB3, GJB4, GJA
A rare, autosomal recessive disorder that presents at birth with an ichthyosis that may range from fine scaling to generalized hyperkeratosis. Erythema may be present at birth but tends to gradually clear by 1 year of age. Collodion-like membranes are rarely seen. The ichthyosis manifests as fine scale, large scale, or thickening of the stratum corneum without scale. Pruritus is common. Thickened areas may be yellow to brown in color and have a lichenified appearance with accentuated skin markings (Fig. 47-25).
Differentiate ichthyosis vulgaris from X-linked ichtyosis based on clinical features
IV tends to be associated with hyperlinear palms and soles, keratosis pilaris, and a family history of atopy.
X-linked Ichthyosis tends to have more severe involvement with larger scale (Fig. 47-2), and commashaped, corneal opacities may be present in half of adult patients.
gene mutated in Superficial epidermolytic ichthyosis
KRT2
Protein: Keratin 2, which is expressed in superficial epidermis
Ichthyosis vulgaris is associated with
Keratosis pilaris
Atopy
SPINK5 gene mutation
associated with cryptorchidism
X-linked recessive ichthyosis
hallmark of ichthyosis
scale
what is the mutation of Epidermolytic Ichthyosis
KRT1 and KRT10
Premature delivery of infants with erythrodermic, edematous, caseous scaling skin resembling excessive vernix caseosa, evolves into dry, scaly skin with follicular accentuation with signs of atopy
Ichtyosis Prematurity Syndrome
A rare disorder consisting of congenital hemidysplasia, ichthyosiform erythroderma, and limb defects, which is found almost exclusively in females.
It is a mosaic disorder featuring red scaly plaques intermixed with normal skin on one side of the body with minimal contralateral involvement. There may be bands of normal skin on the affected side (Fig. 47-24). Limb defects occur ipsilateral to the ichthyosis and range from digital hypoplasia to agenesis of the extremity. There may be punctate calcification of cartilage. Unilateral hypoplasia can involve the central nervous system and cardiovascular, pulmonary, renal, endocrine, and genitourinary systems.
Ichthyosis Linearis Circumflexa
Pathognomonic for Netherton Syndrome
Refsum Disease
Syndromic Forms of Ichthyosis
Epidermolytic ichthyosis
Localized hyperkeratotic plaques with figurate, migratory red patches
Erythrokeratodermia variabilis, Localized type
Disorders Associated with Collodion Membrane
may present with STIPPLED CALCIFICATIONS ON RADIOGRAPH
Most patients of Netherton Syndrome have a specific hair shaft abnormality called ________.
mutations in genes that encode the suprabasal epidermal keratins, keratins 1 and 10, cause ____________ when they affect the highly conserved encoded rod domains necessary for polymerization of keratin intermediate filaments.
Epidermolytic ichthyosis
All patients with ____ have a characteristic corrugated scale that becomes accentuated in areas of body folds.
A rare, progressive, degenerative disorder of lipid metabolism resulting from the failure to break down dietary phytanic acid and its subsequent accumulation in tissues.
Refsum Disease
mutated gene in Ichthyosis vulgaris
FLG - absence of fillagrin
Ichthyosis linearis circumflexa or similar to congenital ichthyosiform erythroderma; trichorrhexis invaginata
Netherton Syndrome
most common ichthyosis
Ichthyosis vulgaris
features that may point to a diagnosis of X-linked ichthyosis
gene mutated in CHILD Syndrome
NSDHL, EBP gene
Thickening of the stratum corneum, evident either clinically or histologically, is termed __________
Hyperkeratosis
Neonatal Ichtyosis - Sclerosing Cholangitis Syndrome
Connexin Disorders
Erythrokeratodermia Variabilis et Progressiva (EKV)
Keratitis-Ichthyosis-Deafness (KID) Syndrome
Fine or centrally tacked-down scale with superficial fissuring; relative flexural sparing, worse on lower extremities; hyperlinear palms and soles
Ichtyosis Vulgaris
gene mutated in Progressive symmetric erythrokeratoderma
LOR, GJB4
Protein: Loricrin, connexin 30.3
there is a characteristic PUNGENT ODOR;
associated with frequent skin infections
Epidermolytic Ichthyosis
Diseases that will present with Collodion baby
may have corneal opacities on the POSTERIOR capsule and delay of onset of progression of labor
X-linked recessive Ichthyosis
