Contact dermatitis usually occurs on areas of your body that have been directly exposed to the reaction-causing substance — for example, along a calf that brushed against poison ivy or under a watchband. The rash usually develops within minutes to hours of exposure and can last two to four weeks.
Can dermatitis last for months?
There are times when the condition gets worse (called flare-ups). Flare-ups are followed by times when the skin will heal. During these times, there may be no signs of atopic dermatitis (called remission). Remission can last for weeks, months, or even years.
It can take a week to 10 days for the rash to resolve, but patients should experience relief from itchiness shortly after treatment begins. Fully evaluating allergic contact dermatitis through patch testing, especially when its recurrent, can provide a patient with substantial quality of life improvements.
Allergic contact dermatitis frequently appears to spread over time. In fact, this represents delayed reactions to the allergens.