Are You Confident of the Diagnosis?
What to be alert for in the history
Lamellar ichthyosis (LI) most often presents in the newborn period as a collodion baby (Figure 1) with pronounced ectropion and eclabium. As the collodion membrane is shed, patients develop diffuse, plate-like scales and sometimes thickening of the palms and soles. The condition does not improve with age. Hypohidrosis and heat intolerance may be extreme.
Characteristic findings on physical examination
Physical examination shows diffuse, large, plate-like, brown-to-grey scales (Figure 2, Figure 3) with variable palmoplantar keratoderma. Variable degrees of scarring alopecia, nail fold inflammation, nail thickening, digital contractures, and ectropion may be present. Short stature occurs in severe forms. Milder phenotypes have been described that fall into the category of lamellar ichthyosis but are clinically intermediate between classic LI and congenital ichthyosiform erythroderma (CIE) (Figure 4). The new unifying nomenclature of ARCI (autosomal recessive congenital ichthyosis) is the most appropriate name for this whole family of conditions.
Expected results of diagnostic studies
Histopathology is not usually helpful in establishing a diagnosis and tends to show marked hyperkeratosis and mild acanthosis with a normal or slightly thickened granular layer. A superficial dermal inflammatory infiltrate is more typical of CIE, but there are no distinct histopathologic differences between the two entities. Electron microscopy may show findings that suggest LI, but this test is not readily available to most practitioners. There are six known genes that lead to the LI phenotype, and commercial testing is available but expensive.
The diagnosis of LI is usually made on clinical grounds. The main differential diagnosis is CIE and, given that they are caused by the same group of genetic defects, they may be a spectrum of disease rather than specific entities.
Intermediate forms of LI might be confused with ichthyosis vulgaris (autosomal dominant, flexural sparing, hyperlinear palms, decreased or absent granular layer), X-linked ichthyosis (only males, prolonged labor, sparing of palms, soles and flexures, comma-shaped corneal opacities, steroid sulfatase deficiency), bullous CIE (autosomal dominant, early blistering, warty scales and spiny ridges, odor), Sjögren-Larsson syndrome (mental retardation, spastic di-tetraplegia, atypical retinal pigmentation degeneration), and Netherton syndrome (severe eczema-like symptoms, abnormal hair showing trichorrhexis nodosa, high IgE level).
Who is at Risk for Developing this Disease?
The incidence of LI is about 1 in 300,000 births. Incidence is not affected by race, nationality or sex. Since the inheritance is autosomal recessive, there will be a one in four chance of a newborn having LI if there is an affected sibling in the family.
What is the Cause of the Disease?
LI is inherited in an autosomal recessive fashion. Six genes have been isolated, TGM1 (the gene for transglutaminase-1), ABCA12, NIPAL4 (also known as ICHTHYIN), CYP4F22, ALOX12B, and ALOXE3. There is limited genotype-phenotype correlation in the group of autosomal recessive congenital ichthyoses although classic LI is most closely associated with the gene for transglutaminase. Patients with a TGM1 gene mutation are more likely to have severe collodion membranes at birth, ectropion, alopecia, and large scales. About 20% of cases of ARCI have no currently identifiable gene abnormality suggesting that there are other genes involved with this phenotype.
These genetic defects cause abnormalities in quantity or quality of intercellular lamellar membranes with resultant transepidermal water loss, epidermal hyperproliferation, and inflammation.
Systemic Implications and Complications
There are no systemic disorders directly associated with LI. Collodion babies are at great risk of developing hypernatremic dehydration, temperature instability, sepsis, and constriction bands that can lead to autoamputation. They should be monitored in a neonatal intensive care unit. Older children and adults may suffer from hypohidrosis and are at great risk of overheating. Avoiding the heat and having a spray bottle on hand are important interventions.
Topical Medical Options
-Education and psychological support
-Tubbing and gentle exfoliation, bath oils or sodium bicarbonate
-Topical antibiotics for infection
Systemic Medical Options
-Oral antibiotics for documented infection
-Psychosocial consulations (psychologist, psychiatry, support groups)
-Otolaryngology consultation for removal of ear canal scale and debris
-Ophthalmology consultation for appropriate eye lubrication and consideration of eyelid surgery
-Orthopedic or physical therapy consultation for digital contractures
Optimal Therapeutic Approach for this Disease
Hydration and soothing of the skin through bathing helps soften the stratum corneum and allows for GENTLE debridement of loose skin. A soft face cloth or an abrasive sponge (eg, loofah sponge) can facilitate this process. Scale removal may be aided with the addition of 1 to 2 handfuls of sodium bicarbonate in the bath tub, although some patients complain of stinging when this is done. Bath oils (eg, RoBathol) provide some comfort and emolliency, but care must be taken to avoid slipping. Bacterial overgrowth on dead skin and resultant odor can be ameliorated with antibacterial soaps or by adding a cup of bleach to a full adult tub.
Lubricating creams and ointments should be applied immediately after the bath, while still moist or after quickly dabbing dry. The choice of product depends on personal taste (a view of internet chat boards shows recommendations covering a wide spectrum) and preference but is preferably thick, fragrance- and chemical-free, and inexpensive. As such, plain petrolatum is a very nice choice. Less greasy creams may be preferred by the patient, and some trial and error may be needed until a particular product is chosen. Some initial recommendations might be Cetaphil, CeraVe, Eucerin, or PDS creams, but patients and families quickly connect with other LI families and share ideas. Browsing www.ichthyosis.com is a good start.
Additional applications through the course of the day are optimal but not always practical and patients may concentrate on exposed, visible areas of skin.
The scalp may need special care in loosening scale and providing lubrication. Overnight application of bland emollients or oils, preferably occluded by a shower cap or saran wrap, facilitates scale removal the following morning. P & S liquid is particularly helpful at loosening scale. Salicylic acid shampoos are helpful.
Eye lubrication is an important part of routine care, particularly if ectropion is present. Various over-the-counter products such as Artificial Tears, Tears Again, Clear Eyes Tears and many others are readily available. Patients should have regular ophthalmologic care.
Localized areas of superficial infection should be treated with mupirocin ointment 2 to 4 times daily. The routine daily use of topical antibiotics is not warranted. Cellulitis or widespread infection requires oral or intravenous antibiotics.
Various topical agents have keratolytic affects and are helpful in removing scale. Ammonium lactate (Lac Hydrin, AmLactin), urea (Ultra-Mide 25, Carmol 10 or 20), salicylic acid (Keralyt), glycolic acid (Aqua Glycolic) are available in many prescription and over-the-counter products. Stinging may limit their use. Systemic absorption must be presumed when these products are used over large body surface areas, and there are reports of toxicity. Young children are at particular risk and salicylates, in particular, should not be used in infants or preschool-aged children.
Response to topical retinoids is variable and irritation may result form their use. Tretinoin, Adapalene, and tazarotene have been tried with good results in some patients. Cost, irritancy, and potential systemic absorption limit the surface that can be treated, so that use on just the face or other exposed areas is most practical. Adding an emollient over the top may help the irritancy. Tazarotene is a pregnancy category X medication.
The oral retinoids, isotretinoin and acitretin, have been used with some success in various ichthyotic conditions, especially lamellar ichthyosis. Long-term doses of 0.5 to 1mg/kg/day of isotretinoin or 0.25 to 0.5mg/kg/day or acitretin are needed, but the effects are life altering for some patients who will wear shorts or a bathing suit for the first time in their life. Both medications are teratogenic, and isotretinoin is a better choice for females of child bearing potential due to its shorter half-life.
Mucous membrane dryness, joint aches, hair thinning, headaches, pseudotumor cerebri, lipid elevations, mood alterations, and bone changes are some other side effects. Laboratory monitoring of liver enzymes, lipids and pregnancy test for women is necessary. Periodic skeletal surveys consisting of a lateral view of the cervical and thoracic spine, a lateral view of the heel and a posteroanterior view of the pelvis should be done.
Most patients will not need regular monitoring and families will rapidly become more knowledgeable regarding the plethora of treatment options than their practitioners.
Yearly or every-other-year visits are advised to monitor for any problems with growth and development, secondary infections, ectropion, ear canal build-up, or digital contractures. Referral to otolaryngology, ophthalmology, or orthopedics may be needed.
Genetic counseling should be offered to all patients and families. The risks associated with future pregnancies and the availability of genetic testing should be clearly and expertly explained. Prenatal diagnosis and preimplantation genetic diagnosis for at-risk pregnancies can be performed but require prior identification of the disease-causing mutations in the family.
Special attention should be paid to the emotional well-being of the patient and family. Counseling should be offered as needed or appropriate. Support groups such as the Foundation for Ichthyosis and Related Skin Types (FIRST) offer patient/family conferences and multiple sources of information. Children may enjoy one of the several camps for children with chronic skin diseases offered by the American Academy of Dermatology (www.campdiscovery.org)
Patients on systemic retinoids need regular laboratory and skeletal monitoring as above.
Unusual Clinical Scenarios to Consider in Patient Management
Collodion babies should be cared for in a neonatal intensive care unit. There is some mortality associated with this condition that is exacerbated if skin care or monitoring for sepsis, dehydration, electrolyte imbalances, and nutrition are compromised.
Bathing suit ichthyosis is a striking variant of LI with sparing of the face and limbs and striking lamellar scale on the trunk. The underlying mechanism involves a mutation in transglutaminase that renders the enzyme sensitive to ambient temperature. Treatment of the affected skin is the same as for classic LI.
Thickened palms and soles will sometimes become secondarily infected with dermatophytes. A trial on an oral antifungal agent such as griseofulvin or terbinafine may result in some improvement. KOH examinations are helpful in diagnosis.
What is the Evidence?
Akiyama, M, Sawamura, D, Shimizu, H. “The clinical spectrum of nonbullous congenital ichthyosiform erythroderma and lamellar ichthyosis”. Clin Exp Dermatol. vol. 28. 2003. pp. 235-40. (LI and CIE share common clinical, histologic, ultrastructural, and genetic features and may be part of a spectrum rather than distinct entities.)
DiGiovanna, JJ, Robinson-Bostom, L. “Ichthyosis. Etiology, diagnosis, and management”. Am J Clin Dermatol. vol. 4. 2003. pp. 81-95. (Overview of all ichthyoses with a good discussion of treatment options.)
Haenssle, HA, Finkenrath, A, Hausser, I, Oji, V, Traupe, H, Hennies, HC. “Effective treatment of severe thermodysregulation by oral retinoids in a patient with recessive congenital lamellar ichthyosis”. Clin Exp Dermatol. vol. 33. 2008. pp. 578-81. (Case report and overview of oral retinoid treatment for ichthyosis with remarkable relief of hypohidrosis.)
Oji, V, Traupe, H. “Ichthyosis. Clinical manifestations and practical treatment options”. Am J Clin Dermatol. vol. 10. 2009. pp. 351-64. (Overview of all ichthyoses with a good discussion of treatment options.)
Oji, V, Traupe, H. “Ichthyosis: differential diagnosis and molecular genetics”. Eur J Dermatol. vol. 16. 2006. pp. 349-59. (Review of the ichthyoses concentrating on diagnosis and the latest genetic findings.)
Oji, V, Tadini, G, Akiyama, M, Blanchet Bardon, C, Bodemer, C, Bourrat, E. “Revised nomenclature and classification of inherited ichthyoses: results of the first ichthyosis consensus conference in Soreze 2009”. J Am Acad Dermatol. vol. 63. 2010. pp. 607-41. (New classification scheme for the ichthyoses emphasizing the use of autosomal recessive congenital ichthyosis [ARCI] as the most appropriate term to encompass lamellar ichthyosis and congenital ichthyosiform erythroderma.)
Vahlquist, A, Ganemo, A, Virtanen, M. “Congenital ichthyosis: an overview of current and emerging therapies”. Acta Derm Venereol. vol. 88. 2008. pp. 4-14. (Review of therapy for ichthyosis including state of the art therapies that are not yet available.)
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