
bro i fucking have this i need help.. to the point where i have it in my mouth, face (entire), and scalp..
You need to get your doctor to check what is happening with your lymph node.
It is most likely you have something causing a dermatological reaction on your skin causing the rash and itch: the most common thing is a yeast / fungal infection - look up how to treat jock itch for this.
However, your skin may have adversely reacted to something like a soap or shower gel that you may not have used before. potentially it can be something like soap powder or whatever your clothing is washed in.
Check whether any of these, your soap, shower gel or any form of body wash you use has changed to one you have not used before?
Be sure to change underclothes for freshly laundered everyday.
You MUST avoid scratching the area - be very careful when you take a shower, do not apply soap or any form of body wash directly to the area, use warm, never hot running shower water yo fully rinse the area at the end of the shower, dry the skin very carefully so as not to damage it and to make sure all moisture is removed as this will only cause further irritation.
A pharmacist can help you in terms of what you can treat the rash with and potential causes
You must see a doctor as soon as possible