Itchiness of skin is normally caused by improper hygienic conditions of skin and is also known as pruritis in more scientific terms. Pruritis or itchy armpits is caused by certain pathogens like bacteria or other microbes that grow if conditions are favorable in order to infect skin pores and release chemicals that act like irritants. Although most cases respond to simple lifestyle modification but if itchiness of armpits affects your sleep or interfere with your normal day to day activities, it is better to seek the help of a registered healthcare provider.
Itchy armpits are a common problem that may develop in following setting:
Human body is exposed to dirt, sweat, grease and body secretions that must be washed off from the body in order to maintain pH and normal skin flora. However, individuals who don't bathe regularly develop itchiness of skin and other parts of the body due to multiplication of bacteria. Moreover, sweat and other body secretions alter the pH of the skin that further release chemicals to irritate superficial skin layers, presenting as itchiness, rash and bumps.
Maintaining optimal hygiene is the most practical solution that requires regular bathing and washing your body with a good antiseptic soap or body wash to kill germs and microbes.
Candida fungal infection due to overgrowth of candida is a very frequent cause of skin infections presenting as itchiness or pruritis. Candida is a normal commensal (or part of normal flora) that is normally present in balance with other bacteria and microbes to populate skin. However, in certain conditions like HIV infection, long standing uncontrolled diabetes or other immunodeficiency states, candida may overgrow beyond normal levels and lead to infection symptoms. Moist areas of the body that are dark and are not usually exposed to sunlight (like groin, armpits and skin folds) are more vulnerable to develop fungal overgrowth. Other causes of fungal overgrowth are corticosteroid therapy, chemotherapy, hormonal disorders, disorders of blood and immune functioning and other environmental/physical factors like hot humid environmental conditions, tight clothing or irritant synthetic underclothing.
Lifestyle modification and dietary changes can modify the expression of infection symptoms and resolve the symptoms in most cases. Cases that are refractory to lifestyle modifications should be managed with anti-fungal medications like azole antifungals and Polyene antifungal medications. Depending upon the severity of infection and pruritis, topical as well as oral antifungal medications, such as clotrimazole (Lotrimin) creams and lotions can be advised. It is also important to identify the risk factors in order to prevent recurrences.
Special sweat glands of the skin (like apocrine glands) discharge their secretions on the surface with the help of special ducts that are responsible for the characteristic odor of skin. However, if these ducts get clogged or blocked, the cysts may develop that are known as Hidradenitis. If no intervention is taken, these cysts may get secondarily infected by bacteria like Staphylococcus aureus leading to the formation of Hidradenitis Suppurativa (cyst containing pus).
Most cases of Hidradenitis Suppurativa resolve after 1- 2 weeks when the pus dries out spontaneously. If the cysts grows larger or become painful, oral antibiotics cam also be prescribed to treat the inflammation and infection. In most refractory cases surgical drainage is also advised.
Excessive sweating is also a significant cause of itchy armpits that lead to chemical irritation due to over-growth of bacteria and microbes in the moist damp environment. Most adult obese individuals have this issue (also seen frequently with hormonal aberration and disorders of basal metabolism of body like hyperthyroidism). Sometimes hyperhidrosis is also observed after starting a new drug or changes in the environmental conditions. Moreover, individuals who work-out a lot or are involved in active physical sports may also experience excessive sweating that is out of proportion to their physical activity.
If the cause is hormonal or systemic, medical management can resolve the symptoms. In other situations, use of Antiperspirants and special soaps also helps in decreasing the intensity of sweating. Other helpful remedies that can manage the symptoms include special medications that act on the glands to decrease the nerve discharge, low-level electrical impulse therapy and even surgical options can be employed to decrease the intensity of sweating.
Miliaria rubra is reported in individuals who live in a hot humid environment and symptoms like sweating develops secondary to prolonged bed rest or hot humid environment. Other than itching, individuals may also complain of red bumps and sandpaper like rash that may respond to behavioral therapy and lifestyle modification.
Sweating can be a response to skin irritants (certain chemicals affect the skin pores and irritate the sweat glands leading to excessive secretion or sweating). Changing the irritant product significantly helps in decreasing the symptoms.
Products with natural ingredients and roll-on product made for sensitive skin can help to avoid itchy underarm skin. If you have developed hidradenitis suppurativa, use of anti-inflammatory drugs or antibiotics helps in alleviating the symptoms.
Inverse psoriasis is a skin condition that is marked by increase turnover of epithelia cells and is more common in obese individuals with thick and deep skin folds. It is characterized by appearance of fissures and primarily involves arm-pits, shins, elbows, under-skin of breast and similar sites. Lesions in this case are usually shiny, smooth, and red with well-defined borders.
A variety of treatment options are available that ranges from low dose steroid therapy and Calcipotriene (Dovonex) to disease modifying drugs like Tacrolimus (Protopic) and similar agents. Phototherapy helps in most patients that do not respond to topical therapies. In severe cases systemic therapy can be employed.
If you symptoms persist, seek the help and assistance of a healthcare professional or a dermatologist.