Dyshidrosis is a skin condition characterized by vesicles on the lateral surfaces of the fingers and toes, as well as on the palms and soles. It is frequent, especially in summer.

Dyshidrosis is a form of eczema called vesicular dermatosis of the hands. Dyshidrosis should be distinguished from other forms of vesiculo-bullous eczema of the hands such as:

• le pompholyx, corresponding to a sudden palmoplantar vesicular and / or bullous rash without redness, usually followed by desquamation for about 2 to 3 weeks and may recur
• thechronic vesiculobullous eczema often progressing to cracking and thickening of the skin
• la hyperkeratotic dermatosis of the hands, Usually affecting men between the ages of 40 and 60 is formed of thick, itchy patches with sometimes cracks in the center of the palms. It is generally of multiple causes, associating contact allergies, irritation and chronic trauma (DIY, etc.)
• severe vesicular damage secondary to mycosis feet or hands.

Little is known about the causes of dyshidrosis but it is known that it is associated with other conditions:

• the mycoses to dermatophytes such as athlete’s foot
• l’hyperhidrosis palmoplantar or increased sweating in the hands and feet. Likewise, it is classic to see dishidrosis appear in summer when the heat increases.
• theatopy : we find a family or personal history of atopy in some studies but not in others …
• l’metal allergy (nickel, chromium, cobalt, etc.), certain plastics (paraphenylene diamine) and Beaume du Pérou is found in some patients
• le tobacco could be an aggravating factor

There are two forms of dyshidrosis:

• simple dyshidrosis, not accompanied by redness. There are only vesicles on the skin
• dyshidrotic eczema, combining vesicles and redness or even scaling.

In both cases the itching is often intense and it can precede or accompany the rash of the blisters.

These are clear (like “water blisters”), often roughly symmetrical on each hand and foot, they tend to merge, then:

• or they dry out, often forming brown crusts.
• or they burst, forming oozing wounds

Dyshidrosis exists all over the world but it seems more rare in Asia. It is more common in adults than in children. It concerns both men and women.

It seems that repetitive contact with irritating products (cleaning products, etc.) and water, as well as prolonged wearing of gloves, are contributing factors to dyshidrosis. Thus the professions at risk of aggravation of dyshidrosis are bakers, butchers, cooks and catering trades, but also health professions and more generally all professions with their hands in water or a hot and humid atmosphere. .

The evolution is often recurrent, sometimes punctuated by the seasons (recurrence in spring or summer for example). Sometimes, dyshidrosis vesicles become infected: their contents become whiter (purulent) and they can cause lymphangitis, a lymph node in the armpit or groin …

Dyshidrosis is defined by the appearance of itchy blisters on the hands and feet. Either they are not accompanied by redness, it is simple dyshidrosis.

Or there is a redness or even peeling, we speak of dishidrotic eczema:

• On the feet: the redness is most often found on the toes, in the hollow of the foot and on the lateral surfaces of the feet
• On the hands: they are more common on the fingers and on the palmar face

The risk factors for dyshidrosis are:

• the mycoses feet and hands with dermatophytes such as athlete’s foot
• l’hyperhidrosis palmoplantar or increased sweating in the hands and feet.
• the allergies metals (nickel, chromium, cobalt, etc.), certain plastics (paraphenylene diamine) and Beaume du Pérou
• le tobacco which could be an aggravating factor repetitive contact with irritating products (cleaning products, etc.), water or a hot and humid atmosphere and prolonged wearing of gloves

It is difficult to prevent dyshidrosis because relapses sometimes occur even while respecting the avoidance of contributing factors:

• perspiration limitation,
• contact with detergents (household products…),
• prolonged contact withwater and frequent hand washing …

Among the measures to be taken to limit the risk of relapses are:

• Avoid contact with irritants and water.
• Avoid contact with products to which you are allergic if the doctor has identified a contact allergy
• Stop smoking which can be a contributing factor.
• Fight against perspiration in case ofhyperhidrosis

The local treatment is based on powerful topical corticosteroids (because the skin of the hands and feet is thick), such as Dermoval, most often applied in creams, in the evening with a gradual decrease in the number of applications

UV therapy (UVA or UVB), applied topically to the hands and feet in a medical environment, can reduce dishidrosis and the number of flare-ups

Heliotherapy, a complementary approach to dyshidrosis

Heliotherapy consists in very moderately exposing (5 minutes per day) the affected hands and feet to the declining sun, around 17 p.m. in summer. It is similar in terms of mechanism to UV therapy delivered to the doctor’s office.