Determining the cause behind a painful, itchy rash often makes the entire ordeal more challenging. Several conditions may cause a red and white rash; in each case, the whiteness could have a ringlike appearance.
Brown Recluse Bite
The bite of a brown recluse spider appears as bull's-eye, with a red, ring-shaped rash surrounding a white ring. The bite burns and itches for approximately ten minutes. It then enlarges and may be accompanied by fever and vomiting, among other symptoms. Treat the bite with an antibiotic ointment to prevent it from worsening. Consult a doctor immediately as well.
Eczema occurs when allergies irritate the skin. The mild rash looks flat and white, but severe flare-ups cause the skin to raise up in red patches. Treat most cases of Eczema with a hydrocortisone cream.
Psoriasis causes a scaly white rash to appear over red, irritated skin. This usually occurs on the elbows and knees. Skin moisturisers, ointments and oral medications and treat psoriasis.
A yeast fungus called tinea versicolor develops colonies on the skin, which change the skin to a reddish brown. White spots may also occur while the rash remains. Treatments include creams and anti-fungal pills.