When melanin, the skin's pigment, bunches together in excess to form dark spots on the back, the condition is called hyperpigmentation. Hyperpigmentation itself has a few different common causes, but the options for remedying dark spots are largely the same regardless of the cause. The American Osteopathic College of Dermatology says most cases of dark pigmentation on the back are not a health concern. However, spots on the skin should be examined by a dermatologist to rule out skin cancer.
Darkened areas of pigmentation on the back are a typical manifestation of long-term exposure to UV radiation from the sun or artificial tanning devices. These areas of dark pigmentation are called solar lentigines, but are more familiarly known as liver, sun or age spots. Spots on the back may also be post-inflammatory hyperpigmentation, a generally temporary reaction to inflammation or injury. A disorder called Addison's disease, consisting of underactive adrenal glands, causes hormonal imbalances that may produce areas of dark pigmentation as well.
If the areas of pigmentation on your back are solar lentigines, they are flat, clearly delineated, rounded and either brown, black or gray. You may see similar spots on the back of your neck and hands, face, shoulders, forearms or lower legs. There may be other signs of damage from UV radiation, such as wrinkles or a leather-like texture to the skin. If the dark pigmentation on your back is a reaction to inflammation or injury, there may be redness, scabs, scars or other signs of the body's healing process. Addison's disease has many symptoms that generally present gradually, notes the National Endocrine and Metabolic Diseases Information Service. Muscle weakness, fatigue, diminishing appetite, weight loss, digestive upset, mood changes, low blood pressure, low blood sugar, salt cravings, headaches and sweats are other signs and symptoms.
A visual inspection, consideration of other symptoms, your medical history, your immediate family's medical history and an account of your sun exposure, sunburns and sun protection habits are key to diagnosing sun-related spots. Your dermatologist may take a sample of affected skin for biopsy, as well. Post-inflammatory hyperpigmentation is generally diagnosed with an examination and consideration of whether there was any recent injury, acne breakout or other problem in the area. A doctor performs an ACTH stimulation test to diagnose Addison's disease. This test measure the levels of the hormone cortisol in the blood and/or urine, explains the National Endocrine and Metabolic Diseases Information Service. A CRH stimulation test is used if abnormal results are produced by the first test.
Solar lentigines are best prevented from appearing and from worsening by protecting the skin on your back from UV radiation. Forgo artificial tanning, advises the AgingSkinNet website of the American Academy of Dermatology. Wear a shirt made from tightly-knit fabric outdoors. If you won't be wearing a shirt, have someone apply a sunblock to your back about half an hour beforehand. Use a waterproof product if you are likely to swim or sweat. Post-inflammatory hyperpigmentation is less likely to occur if you refrain from scratching, picking at or otherwise aggravating injured skin. Addison's disease is usually the result of an autoimmune disorder, and is not typically preventable. However, proper management of known autoimmune conditions may help.
Any type of hyperpigmentation on the back may be faded with topical skin lightening agents. Hydroquinone products used in conjunction with retinoids and mild steroids is a leading course of treatment, according to MayoClinic.com. Cosmetic procedures, including cryotherapy, laser therapy, chemical peels and dermabrasion, can get rid of dark pigmentation as well. In addition, treatment of Addison's disease primarily consists of hormone replacement therapy.