Definition
Skin rash and joint pain are two symptoms that usually occur separately. A skin rash often occurs as part of a bacterial or viral infection or a fungal infection. Joint pain is a frequent companion of a flu-like infection, but can also be a sign of a chronic disease.
Rheumatoid arthritis and other illnesses from the so-called rheumatic form circle belong to it. If skin rash and joint pain occur at the same time, this may in some cases indicate a systemic disease. A systemic disease affects an entire organ system such as the blood and lymphatic system or the musculoskeletal system (muscles and bones).
Several symptoms can occur simultaneously. As with the joint occurrence of skin rash and joint pain, one speaks of a symptom complex. In medical terminology, the term dermatitis-arthritis syndromes has been coined for the joint occurrence of skin and joint symptoms.
A large number of partially rare diseases belong to the Dermatitis-Arthritis-Syndromes. The following sections explain which diseases prefer the symptom complex of skin rash and joint pain. The term dermatitis-arthritis syndromes covers several dozen diseases that cannot be discussed in detail here.
In this section, the most important diseases associated with the joint occurrence of rash and joint pain are listed. We distinguish autoimmune diseases, metabolic diseases, bacterial and viral infections. Autoimmune diseases are based on a misdirected reaction of the immune system.
Here, the defense cells attack the body’s own tissue instead of pathogens. The proportion of dermatitis-arthritis syndromes attributable to autoimmunological processes is large. This group includes a large number of diseases, some of them rare, which is why we will restrict ourselves to the most important ones here.
Probably the most well-known disease, in which an autoimmunological cause is assumed, is rheumatoid arthritis, in the vernacular also simply called “rheumatism“. Joint pain is caused here because the cells of the immune system attack the synovial membrane (synovia) of the joint, causing inflammation. In addition, skin rashes and the typical rheumatic nodules, small, painless hardenings under the skin, can occur.
A disease that can manifest itself in many different ways is Systemic Lupus Erythematodes (SLE). SLE can affect all organ systems of the human body. The spectrum of possible symptoms is correspondingly wide.
It is classified as a dermatitis-arthritis syndrome because skin rashes and joint pain can provide clues to the disease. In SLE, the rash typically occurs on the face and extends in a butterfly shape over the cheeks and nose. The affected skin areas are highly sensitive to sunlight.
An autoimmunological component is also assumed in psoriasis. Psoriatic arthritis, a complicated form of psoriasis, is characterized by inflammation of the joints, which occurs together with the typical skin symptoms. Due to the use of antibiotics, another disease has become less common, in which skin rashes and joint pain occur simultaneously.
This is rheumatic fever, which can occur as an autoimmunological second illness after a bacterial throat infection with streptococci, such as scarlet fever. Skin symptoms and joint pain occur mainly in two metabolic diseases. In the case of diabetes and gout, which is due to a greatly increased uric acid level in the blood.
Both diseases can cause joint pain, joint inflammation and skin changes or rashes. A pronounced itching of the skin (pruritus) is possible in both diabetes mellitus and gout. Lyme disease and syphilis are among the bacterial infections that can accompany skin rashes and joint pain.
Both diseases are caused by spiral-shaped bacteria, so-called spirochetes, which can evade elimination by the immune system for years. Lyme borreliosis has become a well-known disease in Germany due to intensive media coverage. It is transmitted by tick bites.Syphilis was regarded as a sexually transmitted disease and with the increasing spread of the condom it had almost disappeared from Germany.
However, due to the change in risk behavior during sexual intercourse, syphilis has gained significantly in importance again in recent years. In most cases, viral infections affect several organ systems and are therefore to be regarded as systemic diseases. In some cases, skin rash and joint pain occur together as a complex of symptoms.
These include rubella, a viral disease which occurs mainly in children and which has become rarer in Germany today due to vaccination. A typical rubella rash is a patchy skin rash that begins on the face and spreads rapidly to the trunk. In about 30-50% of the cases, a so-called polyarthritis, the inflammation of several joints, accompanies the rash.
The immunodeficiency disease AIDS proceeds in several stages. About 3-12 weeks after infection with the HI virus (HIV), a flu-like appearance appears in about 70% of cases, characterized by severe fatigue, fever, swelling of the lymph nodes, skin rashes and joint pain. As a rule, the disease then changes into a symptom-free and mostly symptom-free state for years.
This is followed by the development of a severe immune deficiency known as stage AIDS. In this stage the body is generally susceptible to infectious diseases, various types of cancer and autoimmune diseases. A common occurrence of skin rashes, muscle and joint pain is not uncommon.
Dermatitis-arthritis syndromes, i.e. the diseases associated with skin rashes and joint pain, also include measles and infectious mononucleosis, better known as glandular fever. At the beginning of the diagnosis is the doctor-patient consultation, the anamnesis. This gives the patient the opportunity to provide detailed information about the duration of the symptoms, the course of the disease, the type of pain and the accompanying symptoms.
This is followed by a thorough physical examination, which includes the affected joints and the skin rash. Depending on the specialty of the doctor, a referral to other specialists may be made. Among other things, a referral to a dermatologist or a rheumatologist is conceivable here.
A blood test can provide information about the nature of the disease. If the physician considers it appropriate, he or she can order special blood tests to examine a possible autoimmune disease as the cause of the symptoms. A virus diagnosis is also possible with the help of blood samples.
If the rash cannot be classified by normal viewing, it can be examined with an incident light microscope. This is a strong magnifying glass with a light source, with which skin changes can be viewed at a high magnification. X-ray technology can help to examine the cause of joint pain more closely.
In many cases, even a normal X-ray image can help to confirm or disprove a suspected diagnosis. Only in rare cases do invasive measures such as a joint puncture become necessary. This may relieve a joint effusion and the fluid can be examined microscopically and in the laboratory.
