Ruby angiomas and seborrheic keratoses: what they are and when to worry?

Ruby angiomas and seborrheic keratoses: what they are and when to worry?

Publication date: 02-10-2023

Updated on: 02-10-2023

Topic: Dermatology

Estimated reading time: 1 min

Ruby angiomas and seborrheic keratoses are very common skin formations that develop mainly in adulthood. Often, those who manifest them have no idea what they are; whether they are benign or malignant conditions and, therefore, how to deal with them. For this reason, we asked Dr. Elena Guanziroli, a specialist in dermatology at Casa di Cura La Madonnina, to better explain what these skin manifestations consist of and when to be concerned.

What are ruby angiomas and seborrheic keratoses?

“Ruby angiomas and seborrheic keratoses are benign skin tumors that typically develop around age 30 to 40 years, with a tendency to increase in later life. They occur mainly in the trunk area, although, in any case, they can show up in any other area of the body,” explains Dr. Elena Guanziroli.

Let’s analyze their characteristics in more detail:

  • ruby angiomas (also called senile hemangiomas or Campbell de Morgan hemangiomas, named after the physician who first studied them in the 1800s) occur as patches or outgrowths about 3 to 4 millimeters in size with a characteristic bright red or purplish color, as the word “ruby” itself indicates. These are superficial accumulations of dilated capillaries that usually originate from an endothelial cell, which are the cells that internally make up blood vessels;
  • seborrheic keratoses are raised growths with a greasy, scaly surface, often lightly speckled, and a brown coloration of varying shades. Initially they may present with small size, 1/2 mm, but can expand going to fill even a whole given skin area. Sometimes, also, multiple seborrheic keratoses converge with each other.

Are ruby angiomas and seborrheic keratoses dangerous?

Ruby angiomas and seborrheic keratoses are benign skin manifestations that cannot develop into malignant tumor forms. In any case, especially for seborrheic keratoses, a differential diagnosis with other conditions is important to pay attention to.

What ruby angiomas should be distinguished from?

Ruby angioma is only one type, but care must be taken, warns the doctor, as the term “angioma” is often improperly used to refer not only to benign skin tumors, but also to more complex congenital vascular malformations such as, for example, what is incorrectly called a “flat angioma” (also vulgarly called a “birthmark”) to refer to a capillary malformation that produces a spot of wine-reddish color that tends to remain constant in size.

Ruby angioma also may be confused with other benign tumors:

  • congenital hemangiomas: vascular lesions that always present with a reddish-purple coloration, but are already detectable in pregnancy and at birth and can also occur under the skin;
  • infantile hemangiomas: again, these are benign red or reddish neoplasms that occur, however, after birth, in the first months of the child's life;
  • angiokeratomas: red, violet or bluish-colored vascular formations with keratotic aspects, which may be present mainly in the genital area, but also on the trunk and other limbs or face;
  • pyogenic granuloma (or globular capillary hemangioma): is a benign proliferation of blood vessels that frequently occurs after trauma and is characterized by rapid growth. It is often found on extreme limbs such as hands and fingers. 

How to distinguish seborrheic keratoses?

Seborrheic keratoses, however, should be distinguished from a number of other formations with which they can be confused such as:

  • solar lentigo, especially when this is in its early stages. Solar lentigo is a flat skin spot, irregular in size and darker in shade than natural skin tone, that appears as a result of sun exposure, especially in old age. Seborrheic keratosis often develops from this, but at a later stage;
  • viral warts, skin growths due to the Papilloma Virus;
  • actinic keratoses, especially when dark in color and present at the level of the face. Actinic keratosis is a form of pre-cancerosis that manifests as a variable-colored, dry, scaly skin spot in skin damaged long-term by sun exposure and UV radiation; 
  • basal cell carcinoma: a malignant tumor that forms due to a mutation to some cells of the epidermis and manifests itself in various ways as a light-colored or brown bump or scar lesion;
  • melanoma, in rarer cases when seborrheic keratoses have dark pigmentation. Melanoma is the malignant neoplasm that arises by mutation from melanin-producing cells (melanocytes) within existing moles or in new formations.

Particularly in doubtful cases related to seborrheic keratoses and for a differential diagnosis, it is essential to consult the dermatologist specialist who will proceed with a dermatoscopy or videodermatoscopy that can magnify the skin formation to view it in more detail. In addition, in rare cases of doubt following the objective examination, the physician will take a biopsy sample.


The causes of ruby angiomas and seborrheic keratoses are still unknown. However, underlying these proliferations is usually a genetic predisposition, thus a familiarity.

Pregnant women also may develop ruby angiomas or spider angiomas (spider-like capillary lesions) as a result of hormonal changes that alter the structure and function of blood vessels, which may subsequently undergo spontaneous regression. It does not, however, appear to be triggered by photoexposure, as one might mistakenly think.

When to visit a doctor?

It is always a good idea to visit a dermatologist if a skin formation occurs or is noticed to be:

  • everted;
  • dark-colored or uneven;
  • prone to bleeding;
  • tending to grow quickly, especially if irregularly.

“For those with a variety of skin lesions, periodic check ups are desirable for preventive purposes with physician-established timelines, while in standard cases, thus without familiarity or positivity to certain malignant diseases, one checkup per year is recommended, preferably before summer and sun exposure,” Dr. Hirsch adds. 

Photoexposure, in fact, can give the skin manifestations a different, darker coloration, so it would be appropriate to make the examination when the skin is not tanned.

How to treat them?

Assuming that both ruby angiomas and seborrheic keratoses are benign conditions, their removal may be necessary if they:

  • are in inconvenient locations so they may bleed or shatter;
  • are cosmetically unsightly;
  • are overgrown.

For ruby angiomas, removal proceeds with techniques such as:

  • diathermocoagulation: using an instrument that emits high-frequency electrical pulses (diathermocoagulator), the tissues of the angioma are “burned” and healed;
  • laser therapy: the laser acts selectively on the angioma to determine its disappearance within a few days.

As for seborrheic keratoses, however, these can be eliminated by:

  • cryotherapy: liquid nitrogen is used to burn by freezing the area of keratosis resulting in cell death and subsequent regeneration of healthy skin;
  • curettage: using a spoon-shaped instrument with a sharp edge called a “curette”. The area of interest is incised and the seborrheic keratosis removed. Curettage eventually may allow analysis of the excised lesion, proceeding with histologic examination;
  • laser therapy;
  • diathermocoagulation.

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