The skin is one of the organs most frequently affected by allergic processes. There are several causes for skin allergy, but all of them usually present with two characteristics: skin rash-stains or reddish patches on the skin and intense itching.
It is important to keep in mind that skin allergies are non-contagious dermatitis, so there is no problem in sharing objects or clothes, coexisting or touching the skin of the patient. Any infectious process that triggers a reaction of similar characteristics must receive a different treatment.
In this article Health2Wellness Blog going to talk about the eight most common causes of pruritic rash, that is, red spots on skin that cause itching.
The Urticaria is a skin lesion, reddish, in plaques and with relief, which causes intense itching; It is usually caused by allergic processes, although it can also be triggered as an adverse effect of taking medications, food consumption, some bites or contact with substances, such as paints, latex, pollen, animal saliva, among others.
Urticaria of allergic start usually in minutes after contact with the allergen.
It is important to clarify that urticaria is a typical manifestation of skin allergy, but may have a non-allergic origin, caused by infections, mainly of viral or bacterial origin. Among the most common causes are influenza, colds, urinary tract infection, pharyngitis, mononucleosis, coxsackievirus infection, HIV, etc.
Urticaria of infectious origin can arise at any time during the infection. In children, 80% of cases of urticaria are of infectious origin, having nothing to do with allergic processes.
Non-allergic urticaria can also arise from heat, cold, physical exercise or pressure on the skin. There are also cases of chronic urticaria, which last more than six months and may not present an apparent cause.
This type of condition has the same origin as urticaria, but it is a more severe form of allergy since it compromises the deeper layers of the skin and also the mucous membranes.
Thus, it can cause swelling of the lips, tongue, eyes and respiratory tract.
This is important to bear in mind that it is a lousy picture that can lead to respiratory distress due to glottis edema or severe asthma, and even evolve towards anaphylactic shock.
Angioedema presents a higher risk of developing in people with a history of urticaria, who are re-expressed to the substance to which they are allergic.
Any person with hives associated with edema of the eyes or lips should seek medical attention quickly.
Contact dermatitis is a kind of skin irritation caused by direct contact with an irritating material. There are two types of contact dermatitis.
Among the most common causes of contact, dermatitis includes bijouterie -mainly those that contain metals such as nickel, chromium and cobalt-, gold, poisonous plants, topical antibiotics, latex, perfumes or cosmetics, rubber, leather, enamels, alcohol, and even scented soaps.
The symptoms of contact dermatitis are a rash, which may itch or burn, may even appear accompanied by small blisters or cracks in the skin. The eruption of contact dermatitis tends to be restricted to the areas that came in contact with the harmful substance; that is, it does not spread to the rest of the skin.
In most cases, dermatitis disappears after a few days if the patient no longer has contact with the substance that triggered the rash. In cases of more intense reaction, corticosteroid ointments may be necessary.
Atopic dermatitis also is known as atopic eczema, is a skin lesion, very common in children, that generally arises in areas of folds, such as the popliteal fossa -the back of the knees-, neck, and ulnar fossa -part of the back of the elbows. In babies, the face is an area that can also be affected frequently.
The causes of atopic dermatitis are unknown, but there is likely to be a combination of dry and irritated skin with immune system defects. It is important to consider that psychological stress can aggravate injuries.
In approximately 85% of cases, atopic dermatitis appears within the first 5 years of life. The eruption of atopic dermatitis is pruritic eczema, which usually has scaly, thick, and obscured plaques.
Atopic eczema is a chronic disease, with periods of improvement relieving with situations in which the rash worsens. About 40% of children stop having the disease spontaneously when they reach adulthood.
In the rest of the cases, this dermatitis has no cure, remaining for the rest of life.
The bites of this type of insect are common causes of allergy in the skin since the mosquito injects its saliva so that it exerts an anticoagulant effect in the sucked blood. Precisely, mosquito saliva is the substance that usually causes allergic reactions in people.
In most cases, the reaction to the bite is small and localized and has as a most common symptom a small reddish rise in the skin with intense itching.
The symptoms of the bite usually arise within 20 minutes and may take up to 2 days to disappear. The more sensitive the mosquito saliva is, the more extensive and intense the reaction to the bite is usually.
However, some people have a higher than average sensitivity to mosquito bites, developing a condition called estrucous prurigo.
In general, after a single bite, they produce several reddish and pruritic lesions, as if they had been stung by several mosquitoes at the same time in different parts of the body. In these cases, the injuries can last up to a month.
Seborrheic dermatitis is also known as seborrheic eczema, is a prevalent and itchy skin infection. This form of dermatitis is a chronic inflammation that arises in areas of the skin that contain a large number of sebaceous glands.
Although they are very similar to another dermatitis of allergic origin, with the appearance of plaques and itching, seborrheic dermatitis is not precisely a skin allergy, although it’s caused by a reaction of the immune system to the presence of a type of Fungus on the skin.
The Scabies, popularly known as mange, is a skin disease caused by the mite Sarcoptes scabies. It is a contagious infection that can spread quickly through close physical contact, which occurs between people who live in the same house or with children in day care centers.
The classic symptom of scabies is a diffuse itching throughout the body, which is usually more intense at night. The typical lesions of scabies are small spots or reddish and embossed balls. In some cases, the lesions can be so minor that they can be camouflaged by the scratches caused by the intense itching.
The areas most affected by the disease are hands, fists, elbows, armpits, nipples, areas around the navel, genitals, knees, buttocks, thighs, and feet. Generally, the backs and the head, palms, and soles of the feet are conserved, that usually are attacked in the children.
The intertrigo candidiasis is a fungal infection of the skin caused by the fungus Candida, which preferentially affects intertriginous areas. The areas where there is a contact of two skins, such as groin, armpits, scrotum, the lower region of the breasts or area between the toes.
These folds are areas especially susceptible to the appearance of intertrigo because they are humid and warm regions, which favor the proliferation of germs, especially fungi.
Intertrigo candidiasis of the skin is manifested by well-reddened patches on the skin with mild scaling and small red spots around it. These lesions may sting or burn and are located in areas of skin folds.
In babies, candidiasis of the skin is common in the areas covered by the diaper.
The superficial mycoses of the skin are also known as dermatophytosis or ringworm. The dermatophyte fungi that cause dermatophytosis are the two genera Trichophyton, Microsporum or Epidermophyton. Dermatophytosis is a fungal infection different from candidiasis, which usually causes intertrigo.
Dermatophytoses can affect several areas of the body such as the scalp, feet, beard, nails or trunk and limbs. Skin fungal infections are contagious and can be transmitted through contact with bedding, towels or ordinary clothes.
The main symptoms of skin mycosis are local itching and redness. Ringworm usually begins with a plaque or reddish and oval-shaped spots, whose center tends to clear up as the days go by. If left untreated, the lesions tend to expand in the form of circles.
The tinea cruris, which is a fungal infection that affects the groin can also occur as a red plate on the inner thighs.
Pityriasis rosea is another common cause of red spots on the skin with intense itching. We don’t know precisely why the disease arises, but studies suggest that it is caused by some of the viruses in the human herpesvirus family, such as human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7). ). The same ones that cause a completely different disease in children, called sudden exanthem or infantile roseola.
Despite being a skin rash of probable viral origin, pityriasis is not contagious.
In most cases, the rash begins with a single round, pink lesion with mild peeling and, generally, the size of a coin. A few days later new lesions similar to the first but smaller begin to emerge from the trunk and around the groin. These red spots can be intensely pruritic and take 1 to 3 months to disappear. In this period, new lesions can appear throughout the body.
With the passing of days, the lesions acquire a ring shape, with a lighter center and reddish and peeling edges.