Pigmentation is the coloring of a person’s skin. The varieties of normal skin color in humans range from people of “no color” (pale, white) to “people of color” (light brown, dark brown, and black). Skin color is a blend resulting from the skin chromophores red (oxyhemoglobin), blue (deoxygenated hemoglobin), yellow-orange (carotene, an exogenous pigment), and brown (melanin). Hyperpigmentation is the term for skin that is discolored, which for most people involves patches of skin that are either lighter or darker than what is normal for the rest of the body.
Blue or Gray
Grayish or blue skin, also called pallor, is a result of a lack of oxygenated blood to the area that is discolored. Blood carries oxygen around the body, and when this is disrupted, a discoloration may occur. The disruption may be to the flow of blood itself, which produces paleness and/or a gray tint to skin tone. A lack of oxygen doesn’t mean that blood flow has stopped, it may be just reduced, causing the skin to change color.
You are probably familiar with the description of people “turning blue” from lack of oxygen when choking or when breathing has stopped. This is the most severe form of this type of skin discoloration. Some conditions that can restrict blood (and oxygen) flow and result in a bluish skin color include anemia, pneumonia, chronic infections such as tuberculosis, heart disease, emphysema, and chronic obstructive pulmonary disease (COPD).
A gray tint to the skin is also an indicator of restricted blood and oxygen flow. Causes of a gray or pallor pigmentation to the skin can be caused by kidney disease or malfunction, cancers that cause blood loss, congestive heart failure, or excess iron.
Red spots are caused by excess blood flow to the skin, whether to fight an infection, a reaction to irritation from friction (a scrape), burning (sunburn), or embarrassment (blushing). Often called rashes, red skin can also be caused by anxiety, excessive rubbing, or excessive cold.
Red skin can have also have more serious causes and indicate an underlying skin condition such as eczema, psoriasis, rosacea, or allergies. These conditions may require specialty pharmacy treatments which can include oral antibiotics and medications that address the root cause of the symptoms of small red dry bumps and red spots. Some skin conditions causing red spots or patches can be exacerbated by stress.
Some skin conditions can also be the result of autoimmune conditions. Autoimmune diseases occur when the body’s immune system mistakenly attacks healthy tissue. The conditions can cause blistering, redness, hair loss and other symptoms. Alopecia areata is a very common autoimmune disorder causing patches of hair loss. Hives is an autoimmune disorder that can cause severe itching and redness all over the body.
The skin is the body’s largest organ and is sensitive to a variety of conditions. Skin conditions are also the first sign of trouble for many serious illnesses including cancers and chronic infections. Doctors recommend getting skin checked by a dermatologist once a year. While the most common reason people visit dermatologists has to do with treating and preventing skin cancers, a dermatologist can also help diagnose more serious illnesses causing skin discoloration, before the condition becomes acute.