What is causing red spots on my skin

Rash: red spots, pustules, and wheals

Rash is not a disease in itself, but rather a symptom of underlying diseases or allergies.
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A large number of different, temporary skin changes are summarized under the term rash. On the other hand, permanent skin changes, such as liver spots, are not referred to as rashes.

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Rash: what is the underlying disease?

What is a rash?

A skin rash (exanthema) usually occurs suddenly. It is a common symptom: Hardly anyone is spared their entire life from red spots, wheals or blisters. The proportion of patients who visit a family doctor's practice because of an itchy rash alone is five to ten percent.

Depending on the type and cause of the rash, a small area of ​​skin, a larger area of ​​skin or the whole body can be affected.

As different as the extent and appearance of exanthema are, so are the causes. A rash can be a symptom of an infectious disease, an allergic reaction, or a parasitic skin condition. Temporary changes in the appearance of the skin can also occur as a side effect of medication (drug eruption).

Red spots on the skin usually have a harmless cause, but can also be a symptom of shingles, glandular fever, syphilis or hepatitis. If the skin changes itch at the same time, there is often an allergy behind it. The body can also react to infections with viruses or bacteria by forming red spots.

Signs of the rash: red spots, pustules, or cracks

A rash often initially manifests itself as raised skin such as small nodules, pustules or wheals. However, it can also appear in the form of red spots without bumps or swellings or show through cracks or skin depressions. Skin deposits such as scales or crusts are also possible.

What types of rash are there?

In the case of a rash, different basic forms are distinguished depending on the appearance.

1. Skin elevations

  • Nodule (papule): Elevation of the skin with a diameter of less than 5 mm

  • Node: Elevation of the skin with a diameter of more than 5 mm

  • Plaque: flat elevation of the skin with a diameter of up to 10 cm

  • Blisters (vesicles): fluid-filled elevation with a diameter of less than 5 mm

  • Bladder (bulla): fluid-filled elevation with a diameter of more than 5 mm

  • Pustule (pustula): elevation of the skin filled with pus

  • Wheal (Urtica): bed-like elevation with fluid storage in the tissue (edema) and a diameter between 0.2 and 10 cm

  • swelling

2. Skin depressions

  • Erosion: superficial damage to the skin

  • Excoriation: deep injury to the skin

  • Ulcer: chronic deep injury to the skin

  • Crack (rhagade)

3. Skin deposits

  • Dandruff (Squama): contiguous areas of peeling epidermis

  • Crust (crusta): dried-up liquid

  • Fluid: Blisters or wheals filled with fluid

4. Rash without elevation or depression

  • Spot (blemish): circumscribed change in color

Other criteria by which a rash is characterized:

  • Reddening of the skin (erythema): formation of red spots on the skin

  • Coarsening of the skin (lichenification): the normal fine fields of the skin are eliminated

  • Arrangement of skin lesions: for example, grouped, scattered or confluent

  • Form of arrangement: for example linear or circular (annular)

  • Sensation of changes in the skin: for example burning or itchy areas of skin

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Rash: cause of red spots, pustules, and wheals

A rash itself is not a disease, but rather a symptom of an underlying medical condition. Sometimes researching the cause can be like looking for a needle in a haystack: From psychosomatic triggers to allergies and intolerance reactions to infectious diseases and internal illnesses, there is a wide range of triggers for a rash.

An overview of possible causes of rash

Viral infections and typical childhood diseases

Infectious diseases caused by bacteria

Allergies and intolerance reactions such as

Rheumatic diseases, autoimmune diseases such as

Infestation by parasites or mycoses (fungal disease) such as

  • Fungal infections (for example athlete's foot)
  • Scabies: The parasitic skin infection is triggered by itch mites, which penetrate the skin and cause very itchy, pin-head-sized blisters (vesicles) and small nodules (papules). Even after the itch mites have been treated and eliminated, the rash can persist for weeks.
  • Bath dermatitis
The who's who of vermin in the house

Skin rash: this is how the diagnosis works

The distribution and appearance of the skin changes are often so typical that dermatologists can in many cases deduce the cause of a rash solely from its appearance and typical accompanying symptoms.

In the doctor-patient conversation, the development of the rash over time (since when has the rash been present? Does it persist or does it worsen in certain situations?) And the accompanying symptoms are in the foreground. In addition, the doctor will inquire about previous illnesses, trips abroad, allergies and medication intake and inquire about similar illnesses in the patient's environment.

During the physical examination, the doctor will check general signs of illness such as fever or fatigue and the condition of the internal organs. The skin areas are carefully examined with an illuminated magnifying glass or a glass spatula in order to precisely assess and describe the skin changes. As a rule, the entire surface of the body including the eyes and, if necessary, the mucous membranes of the nose, mouth and genitals are examined.

Blood test and biopsy

Immunological factors can play a role in a rash. Therefore, blood tests provide indications of inflammatory processes or involvement of the body's own defense system. If the attending physician suspects a contact or food allergy as the cause of the rash, the trigger can be narrowed down and identified by a skin test (prick test) or by determining certain blood components.

The histological examination of a tissue sample (biopsy) provides information about which changes at the cellular level have led to the rash.

The cause of the rash can rarely be clarified; in this case, doctors speak of idiopathic rash.

How is a rash treated?

In many cases, a rash is a result of a virus or bacterial infection. While antibiotics can usually be effective in combating bacterial infections, treating a rash caused by viruses is more difficult. So far, it has only been possible for some of these diseases to target the virus causing the disease with medication, for example herpes infections and chickenpox. For other viral diseases, treatment is limited to alleviating the symptoms.

If the rash is caused by a fungal infection, antifungal drugs are available. Medicines can also be used to treat the rash caused by an allergy. Basically, allergen avoidance (avoidance of contact with the respective allergen) plays an important role in the treatment of allergies. In the event of skin reactions to medication, for example in the form of red spots, the medication concerned should be discontinued in consultation with the doctor and replaced with a better tolerated preparation.

Rashes can also be the result of autoimmune reactions in the body. If there is a disease of the rheumatic form or the immune system, medication is used that influence the activity of the body's defenses. These include anti-inflammatory drugs, cortisone drugs, or immunosuppressive drugs.

Creams soothe itchy rashes

In addition to treating the cause, the symptoms themselves can also be alleviated: special ointments and creams reduce itching and promote healing of the skin. Depending on the shape of the rash, skin care creams to regulate the moisture balance can also support the therapeutic success of skin rashes.

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