The armpit or axilla is a body site prone to infection to certain forms of rashes due to the characteristics of the skin. The skin in the armpit is thinner than other parts of the body and it folds upon itself. With this in mind, it is prone to moisture and also a hair-bearing area.
Allergic contact dermatitis
Allergic contact dermatitis is a common form of rash on the armpit. Take note that this is a delayed-type hypersensitivity reaction which simply means that a reaction does not manifest right away but takes days to manifest. Products applied on the armpit such as antiperspirants, deodorants or shaving creams might contain ingredients that can trigger the rashes.
Intertrigo
Intertrigo is a rash that develops on moist areas of skin folds including the armpit. Aside from the armpit, the rashes can also develop below the breast, groin folds and in the abdominal folds. The rash can be accompanied by fungus, yeast or bacteria that thrive in damp environments.
The prevention is aimed on keeping the skin folds dry. If active, treatment against inflammation as well as curbing down the presence of organisms is recommended.
Irritant contact dermatitis
When it comes to irritant contact dermatitis, it involves a reaction to an external agent in which the skin is exposed to an irritant. This is basically an effect of a direct irritant or toxic effect of a particular agent on the skin.
This form of dermatitis is also the result of applying products such as soaps, deodorants, antiperspirants or washes on the armpits. The rashes can be reddened, scaly or rough. In severe cases, blistering can be present.
Tinea corporis
Tinea corporis is also called as ringworm. There are different types of fungus that causes this infection on the upper skin layer. The rashes appear reddened and accompanied by highlighting on the perimeters. These borders are slightly elevated and there might be a thin layer of scales close to the perimeters of the rash.
Erythrasma
Erythrasma is a rash that develops after infection with the Corynebacterium minutissimumbacteria. Aside from the armpits, the rashes can also affect other parts of the body with skin folds such as below the breasts, groin folds and between the toe webs.
The rashes have reddish or tan color along with minimal wrinkling of the skin. This is known for its coral-red fluorescence upon lighted using a Wood’s lamp. In addition, the rash is effectively managed with erythromycin.
Acanthosis nigricans
Acanthosis nigricans has dark, velvety plaques of skin folds including the armpits. It is usually linked with obesity, insulin resistance, diabetes, certain medications, hormonal changes or cancer. Even though the condition is not directly treated, dealing with the underlying condition can help improve the appearance of the affected areas.