This topic is about understanding and addressing peristomal skin irritation, which can be a common issue for those with stomas. The original poster provides a detailed "fault tree" approach to help both patients and healthcare providers identify and treat these skin problems effectively. Here's a breakdown of the root causes and suggested solutions:

1. Mechanical trauma from frequent barrier or tape removal:
- Use skin protectants like Marathon or 3M Cavilon.
- Apply cold compresses, pure aloe, or adhesive removers.
- Consider Butt Paste with 40% zinc-oxide ointment.
- Use chlorine spray with caution, honey moisturizers, or triple-antibiotic ointment.
- Apply petroleum jelly for protection.

2. Fungal infection:
- Treat with antifungal medications such as Nystatin liquid, tolnaftate, clotrimazole, miconazole, terbinafine, fluconazole, or itraconazole.

3. Contact dermatitis:
- Use stoma powders and wipes.
- Apply topical steroids like betamethasone, tacrolimus, triamcinolone, or hydrocortisone.

4. Allergic reaction:
- Stop using the product causing the reaction.
- Use Flonase, Benadryl (diphenhydramine), or calamine lotion/Ivarest.
- Conduct a patch test on the opposite side of the abdomen for 72 hours to identify the allergen.

5. Pyoderma gangrenosum:
- Confirm with abnormal white blood cell count or CRP levels.
- Seek prescription therapy from a gastroenterologist.

Additional guidance on topical steroids:
- Use foams that dry without affecting wafer adhesion, such as Clobetasol propionate 0.05%, Betamethasone valerate 0.12%, Calcipotriol 0.005% + betamethasone dipropionate 0.064%, and Desonide 0.05%.
- Refer to a potency table to ensure the prescribed preparation is safe for the skin and does not interfere with adhesion.

Additional advice and insights include:
- Be cautious with creams and wafers, as creams under the barrier can cause leaks. If necessary, seal with a large hydrocolloid wafer and maintain a cream-free margin.
- Use temporary measures and reassess each situation, as what works once may not work again.
- For those with severe allergies, consider systemic management and consult an allergist. Use "dry" treatments like powdered antifungal or finely crushed Benadryl, secured with a barrier wipe or tincture of benzoin.
- Be cautious with steroids, as they can thin the skin. Follow potency charts and medical guidance carefully.
- Plan for important events by using temporary protective setups to prevent leaks.