Skin Spots

Skin spots are usually a symptom of various infectious, inflammatory, autoimmune, or age-related conditions. They are changes in skin color that can appear anywhere on the body and may present in different shades.

Symptoms and Causes

Skin spots are alterations in skin pigmentation that appear for various reasons, meaning that they may be harmless and merely an aesthetic concern or the manifestation of a serious disease. Depending on their cause, they may vary in size, color, and shape.

Sun exposure, natural aging, genetic factors, or infectious, inflammatory, or autoimmune diseases are the most common causes of skin spots. Therefore, it is important for a specialist to examine them carefully in order to assess their characteristics and determine whether they pose a health risk.

In most cases, skin spots are benign in nature, so their prognosis is good and treatment is not always necessary. When they are malignant or a sign of disease, obtaining an early diagnosis is important in order to treat the underlying cause as soon as possible and increase the chances of recovery without complications.

Symptoms

The main symptom of skin spots is a change in the color of an area of skin, which may present in different shades:

White spots: more common on the face, chest, back, arms, and legs, which are the areas with the greatest sun exposure and most prone to fungal infections.
Red spots: in most cases, they are temporary and disappear spontaneously.
Brown spots: more common in sun-exposed areas such as the face, hands, and arms.
Pink spots: usually appear on the back or chest and cause itching of varying intensity.
Purple spots: commonly found on the arms, legs, trunk, buttocks, neck, or face.
Yellow spots: usually appear on the palms of the hands or soles of the feet, although they may also be disseminated throughout the body when they are a sign of liver or gallbladder disease, causing yellow discoloration of the skin.
Blue spots: their coloration is due to hyperpigmentation located in the deeper layers of the skin, therefore they should be monitored as a precaution. They may appear in adulthood, although they are common as birthmarks.

Some signs suggesting that skin spots may be the manifestation of an underlying disease include:

Itching.
Pain.
Scaling.
Bleeding.
Crust formation.
Uneven coloration.
Change in the appearance, size, or color of a pre-existing spot.
Sudden onset.

The ABCDE rule helps determine whether a spot may be at risk of being a melanoma (one of the most serious forms of skin cancer):

A (Asymmetry): the two halves of the mole are not identical.
B (Borders): the edges of the spot are irregular, uneven, poorly defined, blurred, or jagged.
C (Color): the same lesion presents different shades.
D (Diameter): the spot measures more than 6 millimeters.
E (Evolution): the size and shape change rapidly.

Causes

The main causes of skin spots are:

Changes in melanin, the natural pigment that gives color to the skin, hair, and eyes.
Alterations in blood vessels.
Inflammation resulting from certain diseases.
Proliferation of bacteria, fungi, or other microorganisms on the skin.

The color of skin spots provides an indication of their cause:

White spots: caused by skin hypopigmentation, meaning insufficient melanin production. They are not usually a sign of serious disease, although they may be an aesthetic concern.

Vitiligo: autoimmune disease causing well-defined, irregular spots due to the loss of melanocytes.
Pityriasis alba: oval or round spots appearing on the face, arms, or torso as a consequence of dehydration or excessive skin dryness. Common in children.
Pityriasis versicolor: fungal infection characterized by white patches on the trunk and extremities.
Milia: small white cysts that appear around the eyes and nose due to trapped keratin. Although common in infants and children, they may also occur in adults.
Hypomelanosis: small spots on the arms and legs caused by photoaging and aging.

Red spots: result from inflammation or blood vessel abnormalities.

Rosacea: inflammatory disease characterized by persistent facial redness and papules. Stress and temperature changes may exacerbate it.
Atopic dermatitis: eczema spreading across the skin, causing spots and itching. It is usually of genetic origin.
Erythema: superficial blood vessels dilate as a result of infection, allergy, or irritation.
Raised moles: accumulation of blood vessels usually associated with aging.
Angioma: bright red protrusions resulting from the accumulation of blood vessels. More common on the trunk and extremities.
Koplik spots: small bluish-white lesions on a red background. They usually begin on the inner cheeks, in the oral mucosa, approximately 2–3 days before the appearance of the skin rash. They are one of the symptoms of measles, an infectious disease.

Brown spots: usually caused by increased pigmentation due to increased melanin production.

Moles or nevi: small protrusions appearing anywhere on the body.
Freckles: circular and small in size. Usually appear on the face and arms, especially in fair-skinned individuals.
Lentigines: may be solar or simple and are a consequence of skin aging.
Birthmarks: present in newborns and usually harmless, although follow-up is advisable.
Seborrheic keratosis: slightly raised lesions that may be bothersome but are not harmful. More common on the back and chest.
Actinic keratosis: rough and scaly lesions that may indicate malignancy. Commonly appear on the nose, temples, ears, and scalp.
Post-inflammatory hyperpigmentation: appears after a skin lesion or inflammation has resolved.
Melanoma: malignant tumor developing in a mole with irregular borders and coloration.
Carcinoma: the most common type of skin cancer, characterized by a non-healing ulcer.

Pink spots: manifestations of various diseases.

Pityriasis rosea: non-contagious, temporary condition that is harmless to the body.
Pink maculopapular rash: rash that begins on the face and rapidly spreads to the trunk and extremities due to rubella infection.

Purple spots: result from rupture of blood vessels due to trauma, natural aging, capillary fragility, coagulation disorders, or nutritional deficiencies. In most cases, they are bruises caused by injury or mild conditions related to venous capillary fragility.

Petechiae: rash that does not disappear upon pressure and may occur due to meningitis, viral infections (COVID-19, cytomegalovirus), medication use (anticoagulants, aspirin), low platelet count, or physical strain (severe coughing, vomiting, childbirth, or intense crying).
Vitamin C deficiency: vitamin C is essential for collagen production; therefore, deficiency weakens capillaries.
Thrombocytopenia: low platelet count, essential for blood clotting. Bruising is one of its symptoms.
Senile purpura: flat spots commonly appearing on the hands and arms of older adults due to age-related blood vessel fragility.

Yellow spots: may be a sign of severe liver or pancreatic disease, although they are often the natural evolution of a bruise before it resolves or the result of excessive intake of foods rich in beta-carotene.
Blue spots: although usually benign moles, they may indicate a more serious medical condition.

Cyanosis: bluish discoloration of the skin due to heart failure or pulmonary disorders.
Raynaud phenomenon: blood vessels in the fingers and toes constrict excessively when exposed to cold, reducing blood flow and causing bluish skin discoloration.
Methemoglobinemia: also known as blue baby syndrome, a blood disorder in which hemoglobin is unable to release oxygen, resulting in oxidation and bluish skin discoloration.

Risk Factors

The risk of developing skin spots increases due to many different factors, since there are numerous causes for their appearance. Some of the most relevant include:

Genetic predisposition.
Aging.
Exposure to radiation, especially sunlight.
Excessive heat.
Intense cold.
Injuries.
Trauma.
Exposure to heavy metals.
Fungal, viral, or bacterial infections.
Changes in hormone levels, which is why they are common during pregnancy and periods of intense stress.
Proliferation of cancer cells.

Complications

Although skin spots are not usually a health risk, they may be the result of serious conditions such as:

Skin cancer.
Persistent hyperpigmentation.
Anxiety.
Depression.
Low self-esteem.

What physician treats skin spots?

Skin spots are usually treated within the specialty of Medical-surgical dermatology and Venereology, although depending on the underlying cause, involvement of specialists in Medical oncology, Infectious diseases, Pediatrics, Angiology and Vascular surgery, or Family and community medicine may also be necessary.

Diagnosis

The diagnosis of skin spots is clinical, as it is based on observation of the lesions. Depending on their characteristics, the specialist may request additional tests to confirm the underlying cause.

Dermoscopy: a high-magnification lens device is used to examine lesions in detail.
Biopsy: a skin tissue sample is obtained for microscopic examination. It allows diagnosis of infections, inflammation, autoimmune disorders, and cancer.
Wood’s lamp examination: long-wave ultraviolet light is used in a dark room to study the characteristics of the spots. It is useful in the diagnosis of infections and cancer.
Molecular testing: analyzes genetic material to determine whether cancer is present.

FISH (fluorescence in situ hybridization): uses fluorescent probes to locate specific DNA sequences on chromosomes and determine whether genetic abnormalities or predisposition to cancer cell development are present.
Tumor marker detection: identifies genetic alterations, proteins, or specific molecules in blood or tissues. It detects cancer or identifies the risk of developing it. It is useful for selecting the most appropriate targeted therapy.
Genetic testing: detects inherited mutations that increase the predisposition to skin cancer.

Blood tests: help detect infections.

Treatment

Treatment for skin spots varies depending on their nature. The most common therapies include:

Vitiligo: phototherapy with ultraviolet radiation and treatment with immunomodulators and corticosteroids to slow disease progression and restore skin color as much as possible.
Pityriasis alba: immunomodulatory medications are used to reduce inflammation and moisturizing creams to rehydrate the skin. In more severe cases, laser therapy may be used.
Pityriasis versicolor: topical antifungals, in the form of shampoos and lotions, or oral antifungals cure the fungal infection.
Milia: exfoliating products are effective as home treatment. If necessary, they are removed using CO2 laser, cryotherapy, or electrocoagulation.
Hypomelanosis: depigmenting or antioxidant creams improve the appearance of the spots. CO2 laser or intense pulsed light may reduce their size.
Rosacea: pharmacological treatment with ivermectin, azelaic acid, or metronidazole reduces inflammation and redness. In severe cases, intense pulsed light or laser therapies are used to close blood vessels.
Atopic dermatitis: adequate skin hydration and topical corticosteroids are recommended to reduce inflammation.
Erythema: symptoms are reduced with topical corticosteroids, antihistamines, and analgesics. Applying cold compresses to the spots is also useful for relieving itching.
Raised moles: treatment is cosmetic, as they are not dangerous to health. They may be removed using CO2 laser or cryotherapy.
Angioma: if they do not disappear spontaneously, propranolol, timolol, cryotherapy, laser technology, or surgery may be used if the lesion is very large.
Koplik spots: since measles is a viral infection, treatment consists of rest, hydration, and analgesic and anti-inflammatory medications to relieve pain and reduce fever.
Brown spots: usually caused by increased pigmentation due to increased melanin production and may be treated with depigmenting creams or peels, laser therapy, microdermabrasion, or cryotherapy.
Seborrheic keratosis: treatment is only required if it causes itching or significant cosmetic concerns. Lesions are removed using liquid nitrogen (cryotherapy), electrodesiccation with electric current, laser therapy, or curettage (tissue scraping).
Actinic keratosis: the most common treatment is cryotherapy, meaning tissue destruction using liquid nitrogen. It may also be removed through scraping, laser therapy, or photodynamic therapy.
Post-inflammatory spots: this type of hyperpigmentation is usually treated with topical medications (vitamin C, retinol, niacinamide, or hydroquinone). In persistent cases, chemical peels, laser therapy, or microdermabrasion may be used.
Melanoma: first, as many cancer cells as possible are removed surgically. Afterwards, personalized treatment with chemotherapy, radiotherapy, or immunotherapy is selected.
Carcinoma: the tumor is removed through surgical excision, Mohs surgery (layer-by-layer removal), electrosurgery, or photodynamic therapy. To eliminate any remaining cancer cells, treatment is completed with radiotherapy, chemotherapy, or immunotherapy.
Pityriasis rosea: lukewarm water relieves itching and moisturizing creams provide hydration and softness to the skin.
Pink maculopapular rash: resolves spontaneously because it is a viral infection. Symptoms are relieved with analgesics, antipyretics, antihistamines, and hydration.
Petechiae: depending on the cause, antibiotics or medications promoting coagulation are administered. Elevation of the affected limb and application of cold compresses are recommended.
Vitamin C deficiency: resolved through a diet rich in citrus fruits, peppers, kiwi, papaya, broccoli, or strawberries (sources of vitamin C) and, in more severe cases, temporary supplementation.
Thrombocytopenia: the most effective approaches are corticosteroid therapy (to slow platelet destruction) or platelet production stimulants. If the problem persists, platelet or plasma transfusion is performed.
Senile purpura: this condition has no cure and is not malignant, therefore moisturizing the area and using sun protection are usually sufficient.
Cyanosis: treatment depends on the underlying cause. Oxygen therapy may be necessary to increase blood oxygen levels, cardiac surgery to repair malformations, bronchodilators to facilitate breathing, or antibiotics to eliminate bacterial infections.
Raynaud phenomenon: the key is avoiding triggers such as cold or stress; therefore, wearing warm clothing and applying relaxation techniques are effective preventive measures. If episodes still occur, vasodilator medications or botulinum toxin injections may be administered.
Methemoglobinemia: the main treatment in severe cases is intravenous administration of methylene blue, an artificial electron acceptor that helps convert methemoglobin (oxidized hemoglobin iron) into hemoglobin.