Ringworm has scaly red spots, or “rings,” on the scalp. But there are several other skin disorders which can cause the same symptom.
This article discusses skin disorders related to ringworm, and the variety of treatments and prevention strategies.
Pictures
Lupus Image credit: korn ratchaneekorn / Shutterstock. 
Lyme disease Image credit: CDC/ James Gathany, 2007. 
Nummular eczema Image credit: Alamy. 
Psoriasis 
Contact dermatitis Image credit: TisforThan / Shutterstock 
Granuloma annulare Image credit: Dermatology11 / Shutterstock 
Pityriasis rosea Image credit: DermNet New Zealand.
Rose Pityriasis
Pityriasis rosea is a normal, mild skin rash that usually takes 6–8 weeks to complete.
It causes a scaly pink patch to develop on the skin, about 2–10 centimeters (cm ) in diameter. It can be mistaken for ringworm when the rash is smaller, and it typically occurs on the torso or the neck.
The rash may be itchy but not painful. It that appear gray, dark brown , or black in dark-skinned people. It that appear pink or red in lighter-skinned people.
A viral infection such as herpes is possibly the cause of rosea pityriasis. But it is not contagious and can not spread through physical contact.
Contact dermatitis
Contact dermatitis is a type of eczema that forms a substance that irritates the skin in response.
An person with contact dermatitis may have an allergic reaction to certain metals, such as nickel or cobalt, cosmetics or soaps ingredients, or materials such as latex.
Often the word “contact dermatitis” is used to describe skin irritation after prolonged hand washing, such as diaper rash or broken skin.
It can be confused with ringworm because contact dermatitis can cause patches of thickened, scaly skin to develop. The patches may be red on a lighter skin, while they may be dark brown, purple or gray on darker skin.
Nummular eczema
Nummular eczema, also known as nummular dermatitis or discoid eczema, is an inflammatory condition causing itchy, swollen skin patches to appear in coin-shaped form. That can happen anywhere on the body.
While they may be smaller, the patches appear to reach 1–4 inches, and may be purple, red or brown. The sensations of scratching or burning can get worse at night, and the patches can leak fluid or crust over.
Which causes nummular eczema is not clear, but a susceptibility to a certain metal, chemical, or medication could be a trigger. In hot climates, or cold , dry climates, the symptoms can also get worse.
Granuloma annulare
Granuloma annulare is an unusual, chronic skin condition. Not infectious or cancerous.
It causes skin patches to develop with a distinctive border of small, firm bumps. The patches may be 1–5 cm in diameter and appear on the legs and arms, and the bumps may be yellow , red, pink, or purple in colour.
Usually the rash is not painful so it’s itchy at times.
The most common form is the annulare of localized granulomas. It affects kids and young adults and typically goes away untreated.
Experts are not sure exactly what causes granuloma annulare, but it may involve:
- sun exposure
- injury to the skin
- viral infections
- certain health problems, such as diabetes, HIV, and thyroid disorders
Psoriasis
Psoriasis is a common long-term skin condition that occurs when the body creates skin cells too quickly. The cells pile up , creating noticeable patches on the skin’s ocean.
The patches can:
- be silvery
- occur with other color changes
- be flaky or crusty
- be itchy or sore
- cause a burning sensation
- appear anywhere on the body — but most commonly on the elbows, knees, scalp, and lower back
The patches can:
- be silvery
- occur with other color changes
- be flaky or crusty
- be itchy or sore
- cause a burning sensation
- appear anywhere on the body — but most commonly on the elbows, knees, scalp, and lower back
Experts believe psoriasis is caused by immune system problems which cause the body to attack healthy skin cells.
It’s not infectious, it can occur in families, but it’s not always inherited. Can cause psoriasis by the following factors:
- hormonal changes
- excessive alcohol intake
- stress
- injuries to the skin, including insect bites and sunburn
- strep throat
- certain medicines, such as anti-inflammatory or high blood pressure medications
Lyme disease
Lyme disease is a bacterial infection caused by a bite from a black-legged tick.
People with Lyme disease appear to develop a circular bull’s-eye rash around the bite mark. On lighter skin, it can appear red or purple. On darker skin, it may appear dark brown or black.
The rash can be itchy or painful and occur with a burning sensation. It may be smooth or have a scaly or crusty outer margin.
In about half of cases, Lyme disease also triggers flu-like symptoms, such as a fever, muscle aches, and fatigue.
Lupus
Lupus is a chronic inflammatory condition on the upper body and face that can cause a red, scaly rash to develop. This rash may sound like ringworm.
An individual suffering from lupus can also experience:
- Tiredness
- joint weakness
- flu-like symptoms
The symptoms that flare up for a couple of weeks or longer before they improve for some time.
Learn more about lupus and find images of the skin changes here.
Treatments
The best treatment strategy depends on the cause for a red, circular rash and an correct diagnosis is important.
Considering the severity of the rash and any other symptoms, a person may benefit from a combination of the following treatments with strategies for home care:
Avoiding the cause
Conditions such as contact dermatitis, nummular eczema and psoriasis may occur in response to stimuli, or may flare up. The detection and avoidance of potential triggers that help to keep the symptoms at bay.
Emollients
Emollients are medications that hydrate and soothe the skin, minimize itchiness, and prevent inflammation.
They come in as lotions, sprays, or replacements for soap. A individual can in most cases buy emollients from a pharmacy without a prescription.
Topical medications and therapies
Medical care also begins with a medicated ointment or cream that may contain antibiotics or corticosteroids.
A doctor can also prescribe injections of corticosteroids or capsules, oral antibiotics or oral antihistamines.
However, for Lyme disease the first-line therapy is antibiotic pills or injections.
For psoriasis, the wide range of medicated creams includes:
- dithranol or vitamin D analog creams to slow skin cell production
- calcineurin inhibitor creams to suppress the immune system
- coal tar, a thick, heavy oil, to reduce itchiness and inflammation
Other therapies
Some types of light therapy can help with granuloma annulare, nummular eczema , psoriasis, and rosea pityriasis, such as ultraviolet light therapy.
Immunosuppressive therapy can also help with nummular eczema and dermatitis in touch.
Cryotherapy, which involves freezing skin areas with liquid nitrogen, can help control the annulare granulomas.
When to see a doctor
See a specialist, such as a dermatologist, if an unexplained rash persists more than a few weeks.
It is especially important to receive professional care if the rash:
- is all over the body
- is painful
- seems to be infected
- begins to blister, especially near the eyes, inside the mouth, or near the genitals
- occurs with any fatigue or joint pain
The American Academy of Dermatology recommend receiving emergency care if a rash:
- accompanies a fever
- accompanies difficulty breathing
- appeared suddenly and is spreading quickly
Summary
Circular and scaly rashes do not necessarily refer to a ringworm. They may be the product of many common health conditions, some more severe than others.
There are a number of remedies available, and the right choice depends upon the cause and extent of the rash.
Anyone that has an unexplained rash should be treated medically. If a rash develops and spreads very rapidly, or if it happens with fever or breathing problems, call emergency services.