There are various causes for a severe diaper rash or diaper rash in general.
Friction caused by a diaper constantly rubbing against the skin can irritate the skin. This usually occurs if the diaper does not fit well or is not properly fastened.
Another diaper rash cause is due to chemical dermatitis. If urine or stool is left in contact with the skin then this can cause the skin to become red and irritated. How much contact time is necessary to cause irritation is variable since it depends on the skin sensitivity of the individual. The skin of a baby tends to be more sensitive than the skin of an adult and therefore less resistant to chemical dermatitis. If the individual has other skin problems such as eczema, then often skin sensitivity to other skin rashes is heightened. The rash problem persists or gets worse as additional contact is made between the offending substances and the irritated skin. If the contact with urine, stool, or mixture of both happens often, the skin may become extra sensitive to these elements and future diaper rashes might develop very easily.
Chemical dermatitis leading to a diaper rash can also occur due to detergent residue that may be left in cloth diapers, the use of scented fabric softeners, the use of bleach when laundering cloth diapers, a skin reaction to the materials used in non-cloth diapers such as fragrances, disposable baby wipes which often contain a host of chemical products, or various creams and lotions that may be used on the skin.
When choosing products to use on a baby's skin, it is important to take note of the chemical ingredients and ensure that those ingredients will not harm the baby's skin. The less chemicals the better for diaper rash and overall healthy skin.
Trapped heat and moisture in close contact with the skin accelerate the development of a diaper rash and therefore, the build-up of these elements should be avoided as much as possible. This means the use of plastic cover pants that do not breathe or in other words allow heat and moisture to escape, should be avoided.
A diaper skin rash may also be caused by what the mother eats when breast feeding. In fact this often occurs after the child is introduced to solid food.
Taking antibiotics is another common cause of a severe diaper rash. Antibiotics as a side-effect for many can cause diarrhea which initiates or makes the diaper rash worse. Antibiotics also destroy good bacteria which can contribute to the development of a severe diaper rash.