Rash on the thigh
A rash on the thigh can affect both the extensor and flexor sides. One thigh can be affected or it can occur on both sides. Strictly speaking, a skin rash is a generalized seeding of uniform skin changes, for example spots (so-called "macules"). This means that the skin changes affect a large part of the skin.
In everyday language, however, other types of skin lesions and localized eczema are often equated with the term rash.
Causes of a rash on the thigh
Various diseases can lead to changes in the skin of the thigh. There are rashes that are limited to one or both thighs as well as those that also affect other parts of the body.
A locally limited rash can indicate a contact allergy, for example. Typically all parts of the body that come into contact with the substance causing the allergy are then affected. Especially professional groups who work with chemicals, paints or building materials can have such toxic or allergic eczema. Such eczema appears abruptly after repeated contact with the substance and leads to redness, blisters, dry and irritated skin.
You can find more about contact allergies here: Allergy rash
Another cause of a rash on the thigh is atopic dermatitis. This hereditary disease leads to dry skin with eczema, which is mainly found on the flexor side (i.e. on the back of the knee). The thighs are often also affected. Typically, both thighs are affected. These rashes are characterized by dry, very itchy and reddened eczema.
On the inside of the thighs, especially in overweight people, the friction and perspiration can cause redness and irritation. This rash, known as "intertrigo", occurs mainly in the folds of the skin due to the strong friction. The risk of fungal, viral or bacterial infections is also increased if you are overweight.
So-called stasis eczema can also lead to rashes on the thighs. Disturbed venous and lymphatic drainage, excessive obesity and immobilization can lead to fluid build-up in the legs and associated skin rashes. The legs are typically reddened, sore, scaly and cracked on both or one side. The eczema has a stocking-like spread and spreads from the bottom up.
More information is available at: Eczema skin
Another cause of a rash on the thigh is shingles (see Shingles on the leg). This affects segment-like skin areas and usually occurs on one side. Small blisters on reddened skin and crusts are typical. The skin is itchy or painful.
In order to correctly diagnose and determine the cause of a rash on the thigh, it is necessary to look at the entire skin once. With this simple examination of the skin, possible suspected and differential diagnoses can be determined with little effort.
Further diagnostic means such as blood tests, smears or fungal preparations provide information about causes such as infections, autoimmune diseases, allergies or chronic skin diseases and help to confirm or rule out suspected diagnoses.
Taking a sample provides information about the cause and is particularly helpful in the case of autoimmune blistering diseases such as pemphigus vulgaris or bullous pemphigoid.
Learn more about this at: What is an autoimmune disease?
Which symptoms are typical?
The symptoms that accompany a rash on the thigh can be varied and depend on the underlying cause.
Shingles, for example, manifests itself as itching, pain and a feeling of tension in the affected skin.
Fungal infections, on the other hand, are mainly characterized by itching and flaking of the skin.
A bacterial infection, such as phlegmon or erysipelas, is usually accompanied by general symptoms such as fever, nausea and fatigue. An unpleasant odor or the evacuation of pus are also typical of abscesses or bacterial infections.
Itching of a rash on the thigh
A very common accompanying symptom of various skin rashes is itching. For most of those affected, itching subjectively leads to the highest level of suffering. It not only causes painful scratching of the skin, but also robs most of those affected from rest and sleep.
Itching is a very typical symptom of parasitic diseases such as itch mites, bed bugs or the like. Other infections, such as yeast infections, also cause itching.
A terrible itch continues to result in allergic rashes. In this case, the itching is not limited locally, but spreads much more over almost the entire body. Contact allergies, neurodermatitis or intertrigo can also cause severe itching.
Itching can often not be treated causally but symptomatically. So-called antihistamines, such as Fenistil, are primarily used to treat itching. As a local measure, menthol or capsaicin ointments can be applied to the affected areas. However, these are only suitable if the skin changes are limited to the thigh. Such ointments are not suitable for use on large areas of the skin.
Rashes are often not only a visual problem, but also lead to annoying discomfort. A burning sensation is a possible symptom of a thigh rash. This can have various causes.
In shingles, the burning sensation is caused by irritation of small skin nerves, also known as neuralgia.
Another common cause of a burning sensation is a damaged skin barrier and damaged epidermis. This is the case, for example, with various chronically recurring diseases such as neurodermatitis or blistering skin diseases (bullous pemphigoid and pemphigus vulgaris).
Classically, however, a burning sensation on the skin is more an expression of nerve damage than direct skin damage.
Pain in a thigh rash
Various thigh rashes may be accompanied by pain. Pain is not an all too rare accompanying symptom of many skin diseases. Shingles is a very classic example of a painful rash on the thigh. Typically, the pain is burning and stabbing.
Abscesses or congestive eczema can also lead to severe pain in the affected thigh. The pain is rather dull, throbbing and palpable in the depth of the thigh.
Erysipelas or phlegmons are also characterized by painful skin changes and redness.
Rather rare autoimmune diseases, such as bullous pemphigoid or pemphigus vulgaris, which belong to the blistering diseases, are also sometimes very painful.
Rash on the inside of the thigh
The inside of the thighs are usually exposed to greater mechanical stress in the form of friction than the outside. Hence, they are more prone to some rashes.
Especially if you are overweight, the friction and, as a result, the formation of sweat is greatly increased. This can lead to irritation of the skin and eczema on both sides of the rubbing areas. This weeping eczema resembles an intertrigo, which is mainly found in skin folds. Redness, itching, small blisters or even flaking are typical. With such eczema there is the risk of an additional colonization of the affected skin with a fungus or bacteria. First of all, it is therefore important to dry out the eczema with the help of inserts or linen towels. In a second step, cortisone ointments and antiseptic additives are used for local therapy. If there is an additional fungal infection, antifungal drugs (antimycotics) are used.
Another possible cause of a rash on the inside of the thighs is a contact allergy. Various chemicals, cleaning agents, substances or the like can lead to allergic or toxic eczema if they come into contact with the skin. These are limited to the contact area of the skin and are temporally related to the contacts.
Ultimately, other, general causes of a rash on the thigh, such as shingles, erysipelas or others, are also possible triggers.
Rash on the outside of the thigh
A rash on the thigh can never be judged by its location alone. Whether a rash can be found on the outside or inside of the thigh does not necessarily say anything about the cause. However, there are skin rashes that tend to show up at certain locations. One possible cause of a rash on the outside of the thigh is shingles. However, this is not strictly limited to the outside, but also affects parts of the back or front of the thigh. A kind of belt-shaped infestation pattern is typical. Contact allergies can also cause a rash on the outside of the thigh. Of course, other causes (see section Causes) are also conceivable for such a rash.
Treatment and therapy of the rash
There are many different options available to treat a thigh rash. A distinction is made between topical and systemic treatments.
Depending on the cause, the therapeutic measures differ fundamentally from each other.
Infectious rashes can be treated with a variety of antibiotic, antiviral, or fungicidal drugs.
The common shingles of the thigh is treated with acyclovir tablets or infusions and topical acyclovir ointments for external use.
An infection with itch mites, on the other hand, can be treated with the active ingredient permethrin.
Many skin rashes are also treated with ointments or cortisone tablets containing cortisone. One example is neurodermatitis.
Erysipelas of the thigh are treated in an inpatient setting with penicillin infusions over a period of several days.
Some rashes, such as intertrigo, require special care.
The treatment of a rash on the thigh is therefore very versatile and cannot be summarized in general terms.
Rash during pregnancy
It is known that skin rashes can occur more frequently during pregnancy that do not exist outside of pregnancy. These are also known as pregnancy dermatoses. The existence of some pregnancy dermatoses is controversial, while others are very recognized and common. Pregnancy can also affect skin rashes in the context of skin diseases (dermatoses) that also occur outside of pregnancy. Skin changes can also occur on the thighs during pregnancy. A common cause is a build-up of lymph in the legs. Slight lymph congestion during pregnancy is natural, but if it is very pronounced it can also lead to eczema, redness and flaking of the thighs and lower legs.
Another possible cause of a rash is the increased friction on the thighs from weight gain.
The disturbed lymph drainage also promotes colonization with a pathogen, so that fungal infections can occur. They are also characterized by redness, flaking and itching. Polymorphic pregnancy dermatosis can also cause a rash on the thighs. This skin disorder, which occurs in late pregnancy, is characterized by a variety of itchy changes in the skin, from flat spots to raised papules (thickening of the skin). An infestation of the abdomen is typical - with a recess in the navel region, the legs, the arms and the lateral parts of the trunk.
The main article can be found here: Rash in pregnancy
Rash on the thigh and stomach
Rashes that affect both the abdomen and thighs can have a variety of causes. A common cause of such skin changes is rubbing of the skin due to excess weight. Especially when skin changes are to be found on the stomach, especially between skin folds, this speaks very much for such a cause. Since overweight is localized in many people on the thighs, buttocks and stomach, skin changes in these areas are also typical.
Fungal infections are also not infrequently the cause of a rash that appears on the thighs and abdomen. Furthermore, skin rashes are possible as part of various underlying diseases, such as neurodermatitis or prurigo.
Itchy, reddish rashes that look like small, red passages in the skin are suspicious for an itch mite infestation. This comparatively common disease is found around the belly button and can also affect the thighs, among other things.
Find out more about this at: What are the symptoms of scabies?