A physician often can diagnose ichthyosis by looking at the skin. A family history is very useful. In some cases, a skin biopsy is done to help to confirm the diagnosis. In some instances, genetic testing may be helpful in making a diagnosis. Diabetes has not been definitively linked to acquired ichthyosis or ichthyosis vulgaris; however, there are case reports associating new onset ichthyosis with diabetes.

Ichthyosis has been found to be more common in Native American, Asian, Mongolian groups. There is no way to prevent ichthyosis.

Ichthyosis is a genetically and phenotypically heterogeneous disease that can be isolated and restricted to the skin manifestations or associated with extracutaneous symptoms. One of which is limb reduction defect known as CHILD syndrome; a rare inborn error of metabolism of cholesterol biosynthesis that is usually restricted to one side of the body. A research done in Egypt proved that it is not a child syndrome and discussed all the case report.

XLI can be suspected based on clinical findings, although symptoms can take varying amounts of time to become evident, from a few hours after birth, up to a year in milder cases. The diagnosis is usually made by a dermatologist, who also typically formulates the treatment plan (see below). STS enzyme deficiency is confirmed using a clinically available biochemical assay. Carrier detection can be performed in mothers of affected sons using this test (see Genetics, below). Molecular testing for DNA deletions or mutations is also offered, and can be particularly useful in the evaluation of individuals with associated medical conditions (see below). Prenatal diagnosis is possible using either biochemical or molecular tests. However, the use of prenatal diagnosis for genetic conditions that are considered to be generally benign raises serious ethical considerations and requires detailed genetic counseling.

The diagnosis of harlequin-type ichthyosis relies on both physical examination and certain laboratory tests.

Physical assessment at birth is vital for the initial diagnosis of harlequin ichthyosis. Physical examination reveals characteristic symptoms of the condition especially the abnormalities in the skin surface of newborns. Abnormal findings in physical assessments usually result in employing other diagnostic tests to ascertain the diagnosis.

Genetic testing is the most specific diagnostic test for harlequin ichthyosis. This test reveals a loss of function mutation on the ABCA12 gene. This gene is important in the regulation of protein synthesis for the development of the skin layer. Mutations in the gene may cause impaired transport of lipids in the skin layer and may also lead to shrunken versions of the proteins responsible for skin development. Less severe mutations result in a collodion membrane and congenital ichthyosiform erythroderma-like presentation. ABCA12 is an ATP binding cassette (ABC) transporter, and is a member of a large family of proteins that hydrolyze ATP to transport cargo across membranes. ABCA12 is thought to be a lipid transporter in keratinocytes necessary for lipid transport into lamellar granules during the formation of the lipid barrier.

Biopsy of skin may be done to assess the histologic characteristics of the cells. Histological findings usually reveal hyperkeratotic skin cells, which leads to a thick, white and hard skin layer.

Overheating: The scaling of the skin prevents normal sweating so hot weather and/or vigorous exercise can cause problems.

Eye problems: The eyelids can be pulled down by the tightness of the skin and this can make eyelids (but usually just the lower one) very red and they are prone to drying and irritation.

Constriction bands: Very rarely children with this condition can have tight bands of skin around their fingers or toes (usually at the tips) that can prevent proper blood circulation to the area.

Hair loss: Severe scaling of the skin on the scalp can lead to patchy loss of hair, but this is rarely permanent.

Treatments for ichthyosis often take the form of topical application of creams and emollient oils, in an attempt to hydrate the skin. Creams containing lactic acid have been shown to work exceptionally well in some cases. Application of propylene glycol is another treatment method. Retinoids are used for some conditions.

Exposure to sunlight may improve or worsen the condition. In some cases, excess dead skin sloughs off much better from wet tanned skin after bathing or a swim, although the dry skin might be preferable to the damaging effects of sun exposure.

There can be ocular manifestations of ichthyosis, such as corneal and ocular surface diseases. Vascularizing keratitis, which is more commonly found in congenital keratitis-ichythosis-deafness (KID), may worsen with isotretinoin therapy.

Mild forms of IBS should be diagnosable from appearance and patient history alone. Severe cases of IBS are hard to distinguish from mild EHK.

A skin biopsy shows a characteristic damaged layer in the upper spinous level of the skin. Again it may be difficult to distinguish from EHK.

The gene causing IBS is known and so a definite diagnosis can be given by genetic testing.

Diagnosis can be made at birth by identifying the symptoms of the child. Ultrastructural diagnosis where tissues are analyzed is using electron microscopy is also conducted. A specimen of skin is obtained via a skin biopsy and analyzed to see any tell tale characteristics.Genetic testing can also be done to identify the mutation on the FATP4 gene associated with fatty acid synthesis. Genetic consultation through a genetic counsellor is done to determine whether the individual has this syndrome and reduces the chances of misdiagnoses with other cutaneous diseases.

As with all types of ichthyosis, there is no cure but the symptoms can be relieved.

- Moisturizers

- Prevention of overheating

- Eye drops (to prevent the eyes from becoming dried out)

- Systemic Retinoids (isotretinoin and acitretin are very effective, but careful monitoring for toxicity is required. Only severe cases may require intermittent therapy.)

Psychological therapy or support may be required as well.

Large and especially giant congenital nevi are at higher risk for malignancy degeneration into melanoma. Because of the premalignant potential, it is an acceptable clinical practice to remove congenital nevi electively in all patients and relieve the nevocytic overload.

Constant care is required to moisturise and protect the skin. The hard outer layer eventually peels off, leaving the vulnerable inner layers of the dermis exposed. Early complications result from infection due to fissuring of the hyperkeratotic plates and respiratory distress due to physical restriction of chest wall expansion.

Management includes supportive care and treatment of hyperkeratosis and skin barrier dysfunction. A humidified incubator is generally used. Intubation is often required until nares are patent. Nutritional support with tube feeds is essential until eclabium resolves and infants can begin nursing. Ophthalmology consultation is useful for the early management of ectropion, which is initially pronounced and resolves as scale is shed. Liberal application of petrolatum is needed multiple times a day. In addition, careful debridement of constrictive bands of hyperkeratosis should be performed to avoid digital ischemia. Cases of digital autoamputation or necrosis have been reported due to cutaneous constriction bands. Relaxation incisions have been used to prevent this morbid complication.

In the past, the disorder was nearly always fatal, whether due to dehydration, infection (sepsis), restricted breathing due to the plating, or other related causes. The most common cause of death was systemic infection and sufferers rarely survived for more than a few days. However, improved neonatal intensive care and early treatment with oral retinoids, such as the drug Isotretinoin (Isotrex), may improve survival. Early oral retinoid therapy has been shown to soften scales and encourage desquamation. After as little as two weeks of daily oral isotretinoin, fissures in the skin can heal, and plate-like scales can nearly resolve. Improvement in the eclabium and ectropion can also be seen in a matter of weeks. Children who survive the neonatal period usually evolve to a less severe phenotype, resembling a severe congenital ichthyosiform erythroderma. Patients continue to suffer from temperature dysregulation and may have heat and cold intolerance. Patients can also have generalized poor hair growth, scarring alopecia, contractures of digits, arthralgias, failure to thrive, hypothyroidism, and short stature. Some patients develop a rheumatoid factor-positive polyarthritis. Survivors can also develop fish-like scales and retention of a waxy, yellowish material in seborrheic areas, with ear adhered to the scalp.

The oldest known survivor is Nusrit "Nelly" Shaheen, who was born in 1984 and is in relatively good health as of April 2016. Lifespan limitations have not yet been determined with the new treatments.

A study published in 2011 in the Archives of Dermatology concluded, "Harlequin ichthyosis should be regarded as a severe chronic disease that is not invariably fatal. With improved neonatal care and probably the early introduction of oral retinoids, the number of survivors is increasing."

Benign congenital nevi can have histological characteristics resembling melanomas, often breaking most if not all of the ABCDE rules. Dermatoscopic findings of the smaller forms of benign congenital nevi can aid in their differentiation from other pigmented neoplasms.

Microscopically, congenital melanocytic nevi appear similar to acquired nevi with two notable exceptions. For the congenital nevus, the neval cells are found deeper into the dermis. Also, the deeper nevus cells can be found along with neurovascular bundles, with both surrounding hair follicles, sebaceous glands, and subcutaneous fat. Such annexes and the hypodermis can also be hypoplasic or, conversely, present aspects of hamartoma.

An extremely rare disease of which only a few isolated cases are known.

Because XLI is caused by a gene mutation or deletion, there is no "cure." One of the aims of treatment is to reduce scaling by removing the excess, flaky scales, and keep the skin hydrated. This can be achieved using a variety of topical creams.

- Keratolytic agents such as Ammonium lactate (Lac-Hydrin) are used to facilitate the release of retained corneocytes.

- Topical isotretinoin

- The topical receptor-selective retinoid tazarotene

Research is ongoing with regard to the use of gene therapy to treat XLI.

The symptoms would appear at birth or shortly after birth. The combination of physical symptoms on the child would suggest they have CHILD syndrome. A skin sample examined under a microscope would suggest the characteristics of the syndrome and an X-Ray of the trunk, arms, and legs would help to detect underdeveloped bones. A CT scan would help detect problems of the internal organs.

CIE has symptoms very similar to Lamellar ichthyosis (LI) but milder and is considered by many scientists to be a variant of that disease, so both diseases are grouped under the title autosomal recessive congenital ichthyosis (ARCI).

The baby is often born in a collodion membrane, a shiny, wax outer layer on the skin and usually with ectropion, having the lower eyelid turned outwards. When the membrane is shed the skin is red with a generalized white scale. Palms, soles and areas on the joints are often affected with hyperkeratosis, a thickening of the layer of dead skin cells on the surface of the skin. In classical CIE (unlike LI) there is little eclabion (eversion of the lips), ectropion and alopecia (hair loss).

Many people with ACRI don't fit neatly into the definition of LI or CIE but have characteristics of both diseases. The definitions of CIE and LI describe the extremes of the range of ACRI.

Congenital Ichthyosiform Erythroderma (CIE), also known as Nonbullous congenital ichthyosiform erythroderma is a rare type the ichthyosis family of skin diseases which occurs in 1 in 200,000 to 300,000 births.

The condition can be diagnosed via exam that reveals; generalized redness; thick, generally dark, scales that tend to form parallel rows of spines or ridges,especially near large joints; the skin is fragile and blisters easily following trauma; extent of blistering and amount of scale is variable

Ichthyosis hystrix is a group of rare skin disorders in the ichthyosis family of skin disorders characterized by massive hyperkeratosis with an appearance like spiny scales. This term is also used to refer to a type of epidermal nevi with extensive bilateral distribution.

Sabinas brittle hair syndrome is inherited as an autosomal recessive genetic trait.

In a study by Howell et al. patients were located and studied by means of complete histories and physical examinations, analyses of serum trace metals, ceruloplasmin concentration, urine and serum amino acids, and routine metabolic urine screens. In addition, serum and urine luteinizing hormone (LH) and follicle-stimulating hormone (FSH) values were determined, and were interpreted in conjunction with total plasma estrogen, estradiol, and testosterone levels. Close examination demonstrated the scalp hairs were very brittle, coarse, wiry in texture, and broke off quite easily with mechanical trauma such as combing and brushing. Some hairs could be visualized in their follicles, which were broken off at the skin line. Most patients had accompanying hyperkeratosis (thickening of the skin) of moderate degree on exposed surfaces. Maxillary hypoplasia (midfacial retrusion) was significant in many patients. The brittle, short hair, reduced eyelashes, crowded teeth, and dull appearance created a characteristic facial appearance. Post-pubertal patients had development of secondary sexual characteristics consistent with their age, except for sparse pubic escutcheons. All cases studied demonstrated some degree of mental deficiency; I.Q.'s ranged between 50–60. A deficiency in eye–hand coordination was also noted.

There are no life-threatening complications after the perinatal period (around the time of birth) and the skin conditions persist but to a lesser degree of severity. Individuals have a favourable prognosis as symptoms can be managed and past the infancy stage are not life-threatening. The red skin edema improves after a three-week period but the ichthyosis scaling persists. Asthma has been recorded in some cases later on in the individual's life and sign of atopic dermatitis persist, follicular hyperkeratosis and small amounts of scaling at the scalp that goes on into adulthood but otherwise the individual continues a healthy life.

The diagnosis is usually based on clinical features present at birth.

Ultrasound in the second trimester may show abnormalities associates with NLS, including polyhydramnios, intrauterine growth restriction, microcephaly, proptosis and decreased fetal motility.

There is no cure for IBS but in the future gene therapy may offer a cure.

Treatments for IBS generally attempt to improve the appearance of the skin and the comfort of the sufferer. This is done by exfoliating and increasing the moisture of the skin. Common treatments include:

- Emollients: moisturisers, petroleum jelly or other emolients are used, often several times a day, to increase the moisture of the skin.

- Baths: long baths (possibly including salt) several times a week are used to soften the skin and allow exfoliation.

- Exfoliating creams: creams containing keratolytics such as urea, salicylic acid and lactic acid may be useful.

- Antiseptic washes: antiseptics may be used to kill bacteria in the skin and prevent odour.

- Retenoids: very severe cases may use oral retinoids to control symptoms but these have many serious side effects including, in the case of IBS, increased blistering.

The prognosis is poor; affected individuals are either stillborn or die shortly after birth. The longest survival reported in literature is of 134 days.

This syndrome is transmitted as an autosomal recessive disorder and there is a risk for recurrence of 25% in future pregnancies.

Ichthyosis en confetti, also known as ichthyosis with confetti, congenital reticular ichthyosiform erythroderma (CRIE) and ichthyosis variegata, is a very rare form of congenital ichthyosis in which healthy patches of normal skin co-exist within the abnormal skin areas. The condition is caused by a frameshift mutation in the keratin 10 gene (KRT10); mutant keratin 10 accumulates in the nucleolus, a sub-nuclear structure, rather than within cellular intermedite filaments like the wild-type protein. Children with the condition exhibit red, flaky skin; however, for reasons not yet totally clear, wild type clonal patches of skin start to appear, in place of the red, flaky skin. Due to the clonal nature of the growth of the normal skin cells, it appears the patient is covered with confetti, hence the name of the condition. It has been hypothesized that this is the result of a combination of mitotic recombination and natural selection within the skin.

The challenge has always been how to deliver the siRNA using a topical method or retroviral vectors and ex vivo gene transfer. In 2011/12 a team at Northwestern University claim to have solved the topical delivery of siRNA dilemma. Personalized siRNA can be delivered in a commercial moisturizer or phosphate-buffered saline, and do not require barrier disruption or transfection agents, such as liposomes, peptides, or viruses. "Topical application of nucleic acids offers many potential therapeutic advantages for suppressing genes in the skin, and potentially for systemic gene delivery. However, the epidermal barrier typically precludes entry of gene-suppressing therapy unless the barrier is disrupted. We now show that spherical nucleic acid nanoparticle conjugates (SNA-NCs), gold cores surrounded by a dense shell of highly oriented, covalently immobilized siRNA, freely penetrate almost 100% of keratinocytes in vitro, mouse skin, and human epidermis within hours after application."

This new discovery may soon offer hope to all suffering from mono-genetic diseases such as EHK. This may lead to promising personalized, topically delivered gene therapy of cutaneous tumors, skin inflammation, and dominant negative genetic skin disorders.

UPDATE: OCTOBER 2014

As of late, Paller reports "we are using a new nanotechnology-based technique called 'spherical nucleic acids' (SNAs) to suppress the production of the abnormal keratin 10 gene that is the most common change leading to epidermolytic ichthyosis. We continue to screen candidate SNAs to find a few that clearly suppress the abnormal keratin 10 gene much more than the normal keratin 10 gene. In the meantime, we have developed several tools towards this effort, which can also be used by other researchers. Most recently we've developed a special 'lentivirus reporter construct' in which we can see through changes in fluorescence whether or not our SNA works."

Dr. Paller and her team recently received more good news with regard to progressing their research. "We just received a grant from the National Institutes of Health (NIH) to continue this effort based on our preliminary data collected with FIRST's funding support. FIRST has been instrumental in furthering our research efforts related to ichthyosis," she said.