Diaper rash, with the fancy medical term 'diaper dermatitis', is basically the unsightly result of pee or poop meeting diapered skin for extended periods. Think of it as an unhappy chemical cocktail party - only, instead of terrible hangovers, you get itchiness and discomfort. While babies are the usual victims, adults with a penchant for diapers or incontinence pads aren't off the hook.

This ghastly rash typically screams for your attention looking all red and angry in lighter skin tones. On darker skin, however, it can play hide and seek by either blending in with the color or lightening up a bit, becoming less pigmented.

But sorry folks, not all rashes are made equal. Diaper rash caused by contact dermatitis is kid-gloves compared to other types. It shows up as redness and inflammation, like an outraged teenager screaming at you for an internet outage. It’s usually accompanied with small raised bumps as well. However, it apologizes and withdraws within two to three days once you stop providing it the irritant it thrives on.

Then we have our candid fellow, yeast diaper rash, medically known as candidiasis. This is one shiny and moist looking rash that's caused by an overabundance of yeast, Candida albicans. This cheeky yeast capitals on warm and moist environments so keeping the diaper area clean, dry, and letting it breathe whenever possible can help curb its enthusiasm.

Eczema, your scaly, itchy mischief-maker, also gate-crashes this party. It usually eggs on your baby to be fussy by looking all red, dry with scaly patches. For adults, topical steroids can help but for babies, a cream with colloidal oatmeal, free from fragrance, can do the trick.

Enter the volatile bacterial diaper rash, bright red with a circular pattern near the anus, causing severe itching or burning. It's the one you don't mess around with - seek immediate medical attention if you suspect this bad boy!

Intertrigo diaper rash is caused by skin getting annoyed with its own self, thanks to friction. Skin barrier creams or ointments can play mediator here, preventing further confrontations.

Next up is the autoimmune culprit, psoriatic diaper rash that ends up creating a patchy reddish rash with silvery-white or gray scales that peel off the skin. Consultation with a dermatologist is key here – since psoriasis isn't a conformist, its treatment varies from person to person.

The last headliner on our diaper rash show is allergic dermatitis, triggered by allergens. This red, itchy party crasher is usually harmless and makes an exit as soon as the allergen is identified and removed.

And just when you thought you got to know all the diaper rash villains, along come other nasties with names so intimidating that they'd make Stephen King shudder - seborrheic dermatitis, impetigo and heat rash.

Finally, diaper rash failing standard OTC treatment or lasting beyond three days mandates an urgent call to your healthcare provider. And still, if you see signs of infection or a fever, run (don't walk) to the nearest healthcare facility.

The mantra in the diaper rash world – prevention is key. Regular diaper changes and creating a barrier against irritants like urine and feces would go a long way. Identify what triggers the rash and work towards avoiding it. Remember, the ‘ABCD’ approach, not the celebrity diet fad you read in that glossy magazine, is your bestie here.