One unique area of chronic dermatitis is the underarm or axillary area. This structure is very tender and sensitive. The underarms have large endocrine sweat glands and hair follicles. All of these structures are potentially able to produce various rashes and harbor various bacteria. Shaving often causes many problems.
The axillae by nature are usually a warm and moist area. This is a perfect setting for Candida yeast and other skin fungal infections. In these cases, application of antifungal creams can bring resolution and relief. Changing the circumstances, like avoiding excess moisture and wearing non-constrictive clothing may help. Antibiotics can kill good and bad bacteria resulting in opportunistic Candida Dermatitis. Candida rashes may be a sign of other problems such as Diabetes Mellitus and other opportunistic disease.
A second form of a rash is caused by bacterial infections. If bacteria are able to enter the skin through the hair follicles, nicks from shaving or pores, an infectious rash can develop. Sometimes they enter through inflamed or eczematous skin or sometimes follow a fungus or yeast into the skin. On occasion, a skin follicle can become plugged as in acne or by an ingrown hair, and bacterial infection, folliculitis, or abscess can ensue. Treatment may include elimination of anything chemical or physical which inflames the skin, and by washing the axilla with a mild antibacterial soap like baby shampoo twice a day. Topical antibiotic ointments and creams may be helpful. In some cases, an antibiotic has to be taken by mouth or as an injection to clear the infection. Sometimes, surgical drainage of the abscess with a drain is necessary.
Another form of infection causing a skin disorder in the axilla is viral. HPV viruses can invade the skin and cause warts. A certain kind of pox virus can cause fleshy domed lesions called molluscum contagiosum. The chickenpox virus can become dormant in a nerve ganglion after a case of chickenpox, and later in life, cause a shingles rash in the axilla.
A very common rash under the arms is caused by contact dermatitis, eczema, and other forms of allergy or hypersensitivity. A person might be allergic to the latex in a bra or to the wool in a sweater. There is an obsession with underarm deodorants, and these can contain all kinds of sensitizing chemicals and fragrances causing these rashes. When this sort of rash occurs, it can cause a cycle of inflammation and infection. The trick is to figure out what is causing the allergy. A lot of soaps and deodorants contain fragrances which can be very sensitizing. Sometimes, physicians will prescribe a 10% solution of aluminum chloride with nothing else added to combat underarm wetness. Since it is an allergy, various cortisone creams can be carefully used to diminish allergic inflammation. Antihistamines can be given to relieve itching with some positive results, as well as a soothing topical such as oatmeal colloid.
These are the most common cause of underarm rash. There are many causes of axillary rashes. Usually, they need to be seen by a physician for meticulous evaluation.
Douglas Beatty M.D.