The signs and symptoms of IT can be classified according to the type they belong to:
The diagnosis of IT is mainly based on the physical examination of the skin. As it is an inherited disorder, a family history of the patient might be useful to detect and classify the disorder. Both approaches can be largely supported by performing a skin biopsy and genetic testing. The presence of systemic disorders such as diabetes mellitus can support the diagnosis of IT .
As IT is mainly an inherited disorder, no permanent cure has been developed, and treatment is largely based on palliative approaches. Very common is the application of creams and emollient oils to hydrate the skin, especially those products containing lactic acid which have proved to be exceptionally effective to treat dry skin. Other classes of chemical compounds which appear effective in treating IT include propylene glycol and retinoids. Exposure to sunlight might improve the condition in certain cases, even thought it can have severe side effects, while the use of oral antibiotics to avoid secondary infections is highly recommended.
Other effective measures can include the use of non-soap cleansers, bathing in salt water, rubbing with a pumice stone to remove scales, or the use of vitamin D supplementations, especially in the most severe cases.
As the severity of IT depends on the type taken into consideration, prognosis too varies according to the case. For the majority of the patients who suffer for mild forms of IT, topical therapy is already sufficient and generally they do well after treatment. On the contrary, prognosis is not good in the most severe forms involving major systemic disorders, where the skin is only the minor clinical concern for the patients.
For example, prognosis is very good with ichthyosis vulgaris, where the major concern is skin moisturization, but not with X-linked ichthyosis, where patients are at higher risk to develop testicular cancer, a far more lethal disorder than IT itself.
The formation of epidermis is the result of an intricate interaction among several components, such as intracellular and extracellular proteins, lipids, nuclear filaments, and key enzymes, each one of them playing a pivotal role in skin development. Any defects in one of this component might be catastrophic and can lead to the occurrence of IT. Although generally inherited, some forms of IT can be acquired. These are usually caused by certain medications, including some of frequent use such as clofazimine, lipid-lowering agents, and butyrophenone   . It should be noted that several important systemic disorders, such as lymphoma   or diabetes mellitus , might also cause IT.
The major genes and proteins involved in IT include:
The incidence and prevalence of IT vary according to the type considered as well as the population under investigation. For instance, prevalence of ichthyosis vulgaris has been estimated to be around 1 case every 250 individuals in UK  and around 2 cases every 100 individual in China . The prevalence of the other less frequent forms is lower, on average around 1 case every 300,000 individuals .
As previously said, the underlying cause of the IT clinical manifestations is the genetic mutations on the genes playing a pivotal role in skin development, which result in a marked increase of keratinization. The major clinical manifestation is undoubtedly the presence of scales all over the skin of the affected person, whose size and thickness vary according to the particular type of IT considered. The degree of scaling is an important pathological factor in itself, as it might cause or extensively influence other important clinical manifestations such as erythema, pruritus, bacterial colonization, and hair loss. Furthermore, as these mutated genes and proteins might play an important role for the entire body, they can frequently cause systemic clinical manifestations.
IT is a chronic condition which requires a lifelong treatment. Therefore, any of the previously indicated measures should be performed permanently during the entire course of the patient’s life, especially to avoid major side effects such as chronic water loss or dangerous skin infection, which might severely affect the quality of life in adults and impair growth and development in children.
The name ichthyosis (IT) derives from the Greek word ἰχθύς (ichthys) meaning fish, with clear reference to the fishy resemblance of the skin of the people affected. The severity of this disorder varies very much, according to the type taken into consideration. The most common type of IT is undoubtedly ichthyosis vulgaris accounting for the 95% of the cases  , which is mild in nature and frequently mistaken for normal dry skin. By contrast, one of the most life-threatening forms is harlequin type ichthyosis, which causes the skin to thicken and frequently results in fatal infections.
These skin disorders are the result of the presence of excessive amounts of dry surface scales due to marked keratinization or cornification, as a consequence of abnormal epidermal differentiation and metabolism. To date, five major types of IT have been officially described, which include ichthyosis vulgaris, lamellar ichthyosis, epidermolytic hyperkeratosis, congenital ichthyosiform erythroderma, and X-linked ichthyosis. These can be differentiated based on the general clinical manifestations, histological findings, as well as genetic makeup .
Ichthyosis (IT) is a term referring to at least 28 different genetic skin disorders, where the skin predominantly appears dry, thickened, scaly and cracked. The name of this group of disorders comes from the Greek word ἰχθύς (ichthys) meaning fish, with clear reference to the fishy resemblance of the skin. This disorder originates from one or more defects in skin development, which might have catastrophic consequences in terms of abnormal clinical manifestations.
There are 5 major types of IT: Ichthyosis vulgaris (the most common of the five), recessive X-linked ichthyosis, autosomal recessive congenital ichthyosis-1 (ARCI1), keratinopathic ichthyoses, and acquired ichthyosis. Each one of these has its own particular repertoire of clinical manifestations, the most common of which include dry skin, rough and red bumps on the skin, atopic eczema, scales, corneal opacities and collodion membrane.
As IT is mainly an inherited disorder, no permanent cure has been developed, and treatment is largely based on palliative approaches. Very common is the application of creams and emollient oils to hydrate the skin, especially those products containing lactic acid which have proved to be exceptionally effective to treat dry skin. Other effective measures can include the use of non-soap cleansers, bathing in salt water, rubbing with a pumice stone to remove scales, or the use of vitamin D supplementations, especially in the most severe cases. IT is a chronic condition which requires a lifelong treatment. Therefore, any of the previously indicated measures should be performed permanently during the entire course of life, especially to avoid major side effects such as chronic water loss or dangerous skin infection.