Vulgar ichthyosis

What is the Ichthyosis vulgaris

Vulgar ichthyosis is the least severe form of hereditary genodermatosis. Together with lamellar ichthyosis, with ichthyosis linked to the X chromosome and epidermolytic hyperkeratosis, vulgar ichthyosis is the most common form of this particular group of skin diseases.

See More Photos Vulgar Ichthyosis

Similarly to the other forms, ichthyosis vulgaris is characterized by the presence of dry skin and formation of scales that make the appearance of the skin similar to that of the skin of fish (hence the term "ichthyosis").

Incidence

Vulgar ichthyosis has a rather high incidence rate which is estimated in one case every 250-1, 000 individuals depending on ethnicity.

This form of ichthyosis affects both males and females of all races, with an autosomal dominant transmission. However, it is important to point out that, in general, genodermatoses most frequently affect Caucasian individuals, while black or Asian individuals are rarely affected by these diseases.

Causes

Vulgar ichthyosis could be caused by an alteration at the level of a gene (thus the mutation is transmitted to the child by one of the carrier parents), or the disease could be the consequence of an induced and spontaneous alteration of the affected subject: in this last case, it means that the sick person with vulgar ichthyosis represents the first case in the family and the pathology has not been transmitted by the parents.

The research has not yet identified the molecular mechanism underlying the vulgaris ichthyosis, but it is assumed that an alteration of filaggrin is the most plausible trigger. Filaggrin is a protein that forms the deep layer of the epidermis, implacable in protecting the skin from external environmental factors and useful for keeping skin hydration under control; it follows that the defect of filaggrin involves alterations in the hydration of the skin, consequently, ichthyosis.

In detail, it is the FLG gene (which encodes, precisely, for filaggrin) to be altered and transmitted from parents to children. The gene may have one or more mutations that lead to an inevitable alteration of the epidermal layer. More precisely, there is an alteration in the cohesion of the keratinocytes, which results in the formation of scales.

The severity of ichthyosis vulgaris usually depends on the quantity and type of genetic mutations.

Symptoms

In general, ichthyosis vulgaris does not occur at birth: it is a subtle disease that takes a few years to evolve and manifest symptoms.

In truth, to be precise, vulgar ichthyosis may appear shortly after birth, but - more often than not - it is simply confused with "dry skin" and, therefore, it is not considered necessary to carry out more detailed investigations or proceed with particular treatments .

In general, a clearer symptomatic picture is diagnosed around the first year of life with a diffuse cutaneous xerosis: the skin has small whitish scales (caused by the altered cohesion of the keratinocytes), particularly in the legs and arms.

In most subjects suffering from vulgar ichthyosis, the face, the palms of the hands, the soles of the feet, the knees, the armpits and the groin ("fold zones") are not affected. This happens because these areas are generally "wetter" than the other areas of the body that, instead, are affected.

However, there are cases of people suffering from ichthyosis vulgaris in which the forehead, the cheeks and the palms assume a different consistency from the normal one, presenting an abnormal thickening.

Itching is a condition that is often found in people affected by ichthyosis vulgaris, caused mainly by the dryness of the skin, the presence of micro-cracks and roughness of the skin. It is clear that, since the ichthyosis of the vulgar is an epidermal manifestation, the internal organs are unharmed.

These symptoms tend to worsen slightly in winter and in areas with an arid climate: in summer, most subjects suffering from vulgar ichthyosis report a marked improvement in the disease, whose manifestations are so reduced as to be almost imperceptible. Indeed, in adulthood, ichthyosis can regress in the presence of a hot-humid climate and then recur in old age.

Associated pathologies

Vulgar ichthyosis is often also associated with atopy (tendency to manifest allergy following ingestion or contact with allergens) and sometimes follicular keratosis.

Among the associated pathologies, eczema (especially of the hands) is also remembered, found in half of the affected subjects.

Furthermore, individuals suffering from vulgar ichthyosis appear to be particularly susceptible to the development of diseases, such as asthma and allergic rhinitis.

Care

Even in this type of ichthyosis - given the causes of genetic origin - a cure has not yet been developed that can definitively cure the disorder.

However, there are treatments (usually topical) able to lighten the discomforts that derive from vulgar ichthyosis.

After medical indication, it would be good to apply emollient and keratolytic substances directly on the skin (which favor desquamation, consequently cell renewal):

Salicylic acid, urea, glycolic acid, ammonium lactate, retinoic acid are the most commonly used substances for keratolytic purposes. However, these active ingredients and the preparations containing them must be used only if prescribed by the dermatologist and only under his strict control, in particular, the use of retinoids requires particular attention, since they can cause different side effects, some of which also serious.

Vaseline, propylene glycol, lanolin represent, on the other hand, the most emollient substances used in topical preparations.

The use of products containing these ingredients must be frequent and constant; if this were not the case, the effect of the treatment would be almost in vain.

Considering that many formulations against ichthyosis vulgaris are characterized by salicylic acid and derivatives, their use in children is not recommended to avoid manifestations of salicylism, a disorder that causes dizziness, nausea and vomiting.

Systemic retinoids, a shock therapy already analyzed in Harlequin ichthyosis, are also useful in the most acute and severe forms of ichthyosis vulgaris; the problem of retinoids per os is that they involve many side effects (dry mouth, mucous membranes, xerophthalmia and alterations of cholesterol and triglycerides), sometimes more serious than the manifestations derived from vulgar ichthyosis itself.

Summary

To fix the concepts ...