Hi,
This could also be an irritation, infection, dermatitis or eczema. The possibility of a poison oak can also be considered. If this is an irritation, it can be brought about by any change in soap or detergent. . Eczema, on the other hand, appears as diffuse red plaques with a poorly defined edge and finely scaled surface. It frequently causes severe irritation. It can be caused by infection or local reaction to skin injury from chemicals or radiation. I t is recommended that you have this evaluated further for proper management. Direct clinical examination is important to determine the diagnosis.Try also to avoid scratching to prevent secondary infection.
Take care and keep us posted.
I'm extremely allergic to the poison family of plants, but have noticed that the appearance of the rash is very unpredictable. I can get it immediately or several weeks later. Furthermore, the palms of my hands never get the rash. I'm not sure why this is, but you're probably the same. Since you touch your penis frequently, as does every man, I think, it's extremely possible you touched a poison plant and then your penis, transferring the oil. Whenever I get poison ivy, I almost always get it on my penis as well as other parts.