Most diaper rashes are the result of sensitive skin irritated by moisture and friction and aggravated by exposure to urine and feces. In most cases, gentle cleansing and the use of any number of over the counter creams that create a protective barrier over the skin are enough to help the rash resolve. There are instances however, where a rash just doesn’t seem to want to go away. Rarely, a stubborn diaper rash may be the sign of a serious underlying illness.
1. Fungal rash. When over the counter creams just don’t seem to work, the most frequent offender is yeast. The most common, Candida, just loves the moist environment inside a diaper. This rash will often be more noticeable in the canyons of the skin folds rather than the over the mounds of flesh, at least when it’s first starting. It can cause a faint peeling, and there will often be tiny red spots surrounding the main area of rash which we call “satellite lesions”. Your doctor will prescribe an an anti-fungal cream which may need to be used regularly for a couple of weeks.
2. Scabies. This rash is generalized over the entire body, but it can have a predilection for the genitalia. It is caused by a tiny mite that parasitizes the skin. The rash is very itchy, particularly at night when the mite tends to be more active. It is common for multiple family members to be affected at the same time. The typical treatment is a one-time application of Permethrin cream.
3. Steroid diaper dermatitis. Steroid creams come in a range of potency. When a topical steroid is covered by a membrane such as plastic wrap or a diaper, the medicine is absorbed more readily and, as a result, the strength of the cream is augmented. Even creams of relatively weak potency become much more powerful, which is why we only use the weakest potency Hydrocortisone in a diaper area (if one is needed at all) for the shortest period of time.
Some doctors inappropriately prescribe a popular combination of an antifungal cream with a medium potency steroid to be applied to the diaper area (see my article on the Seven Medications Pediatricians Should Never Use But Still Do). The result can be severe irritation with the formation of skin ulcers. The treatment for this is to stop the steroid medication.
4. Perianal Streptococcal Dermatitis. You’ve probably heard of strep throat, but you might not have known that children can get strep butt. The same bacteria that causes throat infections can cause an infection of the skin around the anus. The affected area will look bright red. The child may be somewhat ill and run a fever. The diagnosis can be verified by obtaining a culture with a cotton- tipped applicator. The treatment is much like that of strep throat: a short course of an oral antibiotic.
5. Hemangioma. This is not a rash at all but a benign skin growth composed of dilated blood vessels. Hemangiomas are very common in infancy and the majority will resolve by themselves though they often grown in size in the first nine months of life. The ones in the diaper area can be a bit more of a problem because they have a higher propensity for ulcerating and bleeding. A referral to dermatology is sometimes required.
6. Psoriasis. This is a much rarer cause of diaper rash so it is often missed. Psoriasis in infants will often present with diaper rash and no other obvious signs and symptoms. Dermatologic evaluation is typically needed to verify the diagnosis and provide treatment.
7. Zinc Deficiency. The deficiency of this mineral in the diet can cause a severe unremitting rash, often accompanied by a rash around the mouth and hair loss. The child may have an underlying condition that results in defective absorption of nutrients (such as cystic fibrosis) or may be malnourished. A rare genetic disease known as Acrodermatitis Enterohepathica is an inherited disorder of zinc metabolism. These children require expert consultation to address the underlying nutritional deficiencies.
8. Langerhans Cell Histiocytosis. This is a poorly understood group of disorders that affect the cells that originate from the bone marrow as well as a specific type of skin cell known as the Langerhans cells. Children with this condition have a variety of symptoms, including chronically draining ears, a rash behind the ears, bone lesions and blood disorders in addition to severe diaper rashes that are generally unresponsive to common treatments.
Even with the most meticulous skin care, most infants will develop mild irritation in the diaper area from time to time. Most diaper rashes are transient and respond quickly to traditional treatments. The ones that don’t improve require evaluation by a physician. Rarely, a diaper rash can be a sign of a more serious malady.