What is Cutaneous Angiofibroma?
Cutaneous angiofibroma refers to a range of skin conditions that look different but, under the microscope, show the same results. These conditions are harmless growths made up of star-shaped and elongated cells, tiny blood vessels with widened openings, and rings of collagen, a type of protein in our body. Cutaneous angiofibromas can be found on various parts of the body. On the face, they are often called fibrous papules or adenoma sebaceum. On the penis, they are termed as pearly penile papules; under the nail, they are known as periungual angiofibroma or Koenen tumors. When they appear in the mouth, they are known as oral fibromas.
The facial form of cutaneous angiofibroma is one of the clear signs of a genetic disorder called tuberous sclerosis, which affects various body parts such as the skin, kidneys, heart, brain, and lungs. Usually, these facial angiofibromas start to appear during childhood or early adulthood. The presence of at least three facial or two periungal angiofibromas are significant indicators of tuberous sclerosis. These facial angiofibromas are also seen in other conditions like multiple endocrine neoplasia type 1 and Birt-Hogg-Dube syndrome.
Pearly penile papules are enduring, non-problematic bumps located on the rim of the penis, most commonly seen in men who are not circumcised.
What Causes Cutaneous Angiofibroma?
Tuberous sclerosis is the result of changes in the genes named tuberous sclerosis complex 1 (TSC 1) and tuberous sclerosis complex 2 (TSC 2). These genes are responsible for creating the proteins hamartin and tuberin, respectively. If these genes don’t work properly due to these changes or mutations, it can lead to this disease.
MEN-1 is due to a change or mutation in the MEN1 gene. This gene’s main job is to produce a protein called menin, so if it’s not working right, it can lead to this condition.
Lastly, Birt-Hogg-Dube syndrome happens because of a mutation in the FLCN gene. This gene is tasked with creating a protein called folliculin. If this gene has a mutation, it results in this disorder, as it can disrupt the proper creation and function of folliculin.
Risk Factors and Frequency for Cutaneous Angiofibroma
Tuberous sclerosis is a condition that results in various symptoms. Seventy-five percent of people with this condition will develop a type of skin abnormality known as angiofibromas. Some other related issues you could see are:
- Periungual angiofibromas, which occur under the nails, are less typical in children but the occurrence increases to 40% in adult patients.
- Periodical angiofibromas, a symptom of tuberous sclerosis, affecting 30% to 60% of patients.
- Oral fibromas, another type of skin abnormality, which can happen in 30% to 70% of patients and are more typical in adults than children.
- Pearly penile papules, skin changes occurring in about 30% of males after puberty.
Signs and Symptoms of Cutaneous Angiofibroma
Fibrous papules are single, rounded and skin-colored to red bumps usually found on the central face, typically around the nose and cheeks. They sometimes have tiny blood vessels visible on their surface. In a condition called tuberous sclerosis, similar bumps called angiofibromas usually appear symmetrically on the cheeks, nose folds, nose, and chin. These may start as red spots that transform into red to brownish-red bumps, which can merge to form larger patches.
Pearly penile papules are white, rounded, small bumps found on the head of the penis. They are arranged in multiple layers and circles around the ridge of the penis. In tuberous sclerosis, another kind of bumps called periungual angiofibromas can appear along the sides or base of the nails, especially on the toes, from late childhood to early adulthood. These can cause pain and deform the shape of the nail. Oral fibromas, another type of bumps, are most frequently found on the gums but can also appear on the inner cheeks or lips, and occasionally, on the tongue.
In Birt-Hogg-Dube syndrome, a skin condition that affects the hair follicles, you may find fibrofolliculomas, perifollicular fibromas, and trichodiscomas. These bumps range from skin-colored to lighter than the skin and are typically found on the head, neck, or upper torso.
Testing for Cutaneous Angiofibroma
Diagnosing angiofibroma involves taking a patient’s medical history, conducting a physical exam, and carrying out a skin biopsy. In cases where conditions like tuberous sclerosis, MEN-1, or Birt-Hogg-Dube are suspected, genetic testing is needed. In these situations, comprehensive testing is also done to check for any tumors related to these conditions.
Treatment Options for Cutaneous Angiofibroma
Several treatments are currently available for a type of benign skin growth called angiofibromas. These treatments range from removing the growths by shaving or freezing (cryotherapy), destroying them with electric current (electrodesiccation) or heat (radiofrequency ablation), smoothing them with dermabrasion, using lasers, to applying a topical medication called podophyllotoxin. However, these methods can sometimes cause side effects such as scarring, skin pigment changes, and pain. Moreover, these growths can return in up to 80% of cases, leading to the need for further treatments.
One promising treatment is a topical medication called rapamycin, which works by slowing down cell growth. While this has been proven to be safe and effective, longer-term studies are still needed. Combining multiple treatments, such as laser treatments and topical medications like timolol or rapamycin, may also be beneficial.
Rapamycin has been growing in popularity for treating angiofibromas. This is because it inhibits a protein involved in cell growth and reduces the production of a substance that promotes the growth of new blood vessels. Research has shown that using it as a topical treatment can clear angiofibromas as long as the medication is used. However, creating the right concentration of this medication is not standardized and may result in some mild side effects like irritation and redness. Furthermore, the cost can be quite high, dependent on the duration of treatment required.
Another treatment option is beta-blockers, which have been used for many years for treating vascular lesions. For example, a beta-blocker called propranolol can greatly treat hemangiomas, a type of vascular tumor in children. However, it can have side effects, such as low blood sugar levels. Applying a beta-blocker named timolol topically has also successfully treated superficial hemangiomas. Beta-blockers work by interfering with certain chemical reactions that contribute to the growth of blood vessels and promote cancerous growth.
What else can Cutaneous Angiofibroma be?
When looking at skin conditions on the face, angiofibromas (raised red spots) often get mixed up with other skin issues. These include acne, skin tags, those brown moles that seem to be a part of the skin (called intradermal melanocytic nevi), a type of skin cancer known as basal cell carcinoma, and tumors associated with sweat glands and hair follicles (adnexal tumors).
Additionally, it’s easy to confuse angiofibromas around the fingernails and toenails with common warts (verruca vulgaris) and bony growths under the nails (subungual exostosis).
Pearly penile papules (small skin-colored bumps that circle the rim of the head of the penis) can be mistaken for genital warts (condyloma acuminatum) and a viral skin infection usually seen in children and young adults (molluscum contagiosum).
What to expect with Cutaneous Angiofibroma
Angiofibromas are non-cancerous growths, but they don’t get better on their own. When there are several, they can lead to notable changes in appearance, bleeding, itchiness, and redness. Therefore, it’s essential to have an effective treatment.
