What Is This Adolescent’s Asymptomatic Purple Plaque?
A 16-year-old white adolescent presented with a well-circumscribed lesion of 3 years’ duration on the right side of her buttocks.
The lesion had been slowly increasing in size, but without any associated symptoms. Her past health history was unremarkable, and she was not on any medication. There was no history of trauma to the site.
Physical examination showed a well-demarcated, dark purple plaque on the right side of the buttocks. The rest of the physical examination findings were unremarkable.
What’s your diagnosis?
(Answer and discussion on next page)
Answer: Angiokeratoma
Angiokeratoma refers to a benign vascular telangiectasia in the papillary dermis that is associated with hyperkeratosis of the epidermis.1 The disorder is characterized clinically by solitary or multiple dark red or black papule(s), nodule(s), or plaque(s), mostly with a verrucous surface; histologically, it is characterized by dilated blood vessels in the papillary dermis with overlying epidermal hyperkeratosis and/or acanthosis.2
The condition was first described by Pierre-Antoine-Ernest Bazin in 1862.3 The term angiokeratoma was coined by Vittorio Mibelli in 1889.4 Numerous variants of angiokeratoma subsequently have been described.
EPIDEMIOLOGY
The prevalence of angiokeratoma is estimated to be approximately 0.16% among the general population.2,5 The disorder is most prevalent in the white population and is less commonly observed in dark-skinned populations.2 The peak age of onset and the sex ratio vary among the variants of angiokeratomas.
ETIOPATHOGENESIS
Presumably, the telangiectasia of angiokeratoma results from a decrease in the supportive elastic tissues in the walls of the blood vessels, from an increase in localized venous hypertension, or from vascular malformation.1 Predisposing factors include mechanical trauma and chronic irritation. Cold temperatures have been implicated in the development of angiokeratoma of Mibelli.1 The increase in proliferation of the epithelium may be associated with an expression of matrix metalloproteinase-9 localized in the epidermis just beneath the horny layer of the angiokeratoma.6 Friction in an area in close proximity to the vascular spaces also may play a role.7
HISTOPATHOLOGY
Histologic findings include papillary dermal dilated thin-walled blood vessels, lined by a layer of endothelial cells, with hyperkeratosis and acanthosis of the overlying epidermis.1,8 There is no involvement of the deep dermis.
CLINICAL MANIFESTATIONS
Based on clinical appearance, location, and historical aspects, 5 main clinical variants have been recognized: solitary angiokeratoma, angiokeratoma of Fordyce, angiokeratoma of Mibelli, angiokeratoma circumscriptum, and angiokeratoma corporis diffusum. Most lesions are asymptomatic, but irritation, pain, a burning sensation, and itching occasionally may occur.2,5
Solitary angiokeratoma is the most common variant and accounts for 70% to 83% of cases.2,5 The condition was first described by Imperial and Helwig in 1967.9 Clinically, a solitary angiokeratoma presents as a bluish black to black, warty, keratotic papule, and less commonly presents as a nodule or plaque.2 Sites of predilection include the lower extremities, the buttocks, and the lower abdomen.7 Rarely, solitary angiokeratoma may involve the oral cavity, mainly the tongue and tonsillar pillar.7 The condition most frequently is observed in the male population from the teenage years through the 40s.5
Angiokeratoma of Fordyce accounts for 14% of angiokeratomas.2 The condition occurs mainly in men over the age of 40.10 Clinically, angiokeratoma of Fordyce presents as multiple, well-circumscribed, dome-shaped papules, from 2 to 5 mm in diameter, mainly on the scrotum. Rarely, the lesions can be found on the penile shaft, glans penis, inguinal folds, abdomen, buttocks, and upper thighs in males and on the labia majora in females.10 The color of the lesions may be red, blue, purple, dark red, or bluish black.
Angiokeratoma of Mibelli is characterized by multiple dark red papules less than 5 mm in diameter, the surfaces of which become hyperkeratotic with time.1,2 The lesions occur mainly on the dorsa of the hands and feet.2 Girls in the first 2 decades of life most frequently are affected.
Angiokeratoma circumscriptum, the rarest of the angiokeratomas, typically presents at birth or shortly thereafter as a cluster of elevated, hyperkeratotic, dark red to purple or black aggregated papules.11 The lesions usually are situated unilaterally or otherwise asymmetrically on the legs and feet but also may occur on the thighs, buttocks, and occasionally elsewhere on the body.11 With time, the aggregated papules may coalesce to form hyperkeratotic verrucous plaques in a zosteriform distribution.6 The female to male ratio is 3 to 1.6 The condition may be associated with Klippel-Trénaunay syndrome, Cobb syndrome, nevus flammeus, cavernous hemangioma, and traumatic arteriovenous fistula.6
Angiokeratoma corporis diffusum typically presents with innumerable small, red to black papules on the lower region of the trunk, buttocks, and thighs.2 Mucosal involvement is common.2 The onset usually is in early childhood. Angiokeratoma corporis diffusum often is a dermatologic hallmark of Fabry disease (ɑ-galactosidase A deficiency), GM1 gangliosidosis (β-galactosidase deficiency), fucosidosis (ɑ-l-fucosidase deficiency), β-mannosidosis (β-mannosidase deficiency), sialidosis (sialidase deficiency), and Kanzaki disease (ɑ-N-acetyl galactosaminidase deficiency).12 While Fabry disease has an X-linked recessive mode of inheritance with male predominance, the other disorders have an autosomal recessive mode of inheritance with no sex preference.
DIAGNOSIS and DIFFERENTIAL DIAGNOSIS
The diagnosis is mainly clinical. The use of dermoscopy facilitates visualization of dark or red lacunae, a whitish veil, peripheral erythema, and a hemorrhagic crust, which are features of angiokeratomas.5 A skin biopsy or referral to a dermatologist should be considered if the diagnosis is in doubt.
The differential diagnosis of angiokeratoma includes melanocytic nevus, verrucous epidermal nevus, melanoma, verruca vulgaris, verrucous hemangioma, hereditary hemorrhagic telangiectasia, lymphangioma circumscriptum, pigmented basal cell carcinoma, Spitz nevus, seborrheic keratosis, dermatofibroma, and pyogenic granuloma.1
COMPLICATIONS
Rarely, intermittent bleeding following trauma can occur and can result in a hemorrhagic crust.1,5 Angiokeratomas are prone to thrombosis. The condition can be cosmetically unsightly and may lead to anxiety and social embarrassment.
PROGNOSIS and Management
Without treatment, angiokeratoma lesions tend to persist and may increase in size and number with time.1 Spontaneous regression is rare.
The underlying cause should be looked for and treated if possible. Evidence of increased scrotal venous pressure such as varicocele and inguinal hernia should be sought in patients with angiokeratoma of Fordyce, the treatment of which may lead to regression of the angiokeratomas.11 Likewise, an underlying metabolic disorder should be looked for in patients with angiokeratoma corporis diffusum. Otherwise, apart from reassurance, treatment is not required for the majority of patients with angiokeratomas.
For those who desire to be treated for cosmetic reasons, and for those with symptomatic lesions, options include surgical excision, cryotherapy, electrocautery, sclerotherapy, and laser therapy.1,10
Alexander K. C. Leung, MD, is a clinical professor of pediatrics at the University of Calgary and a pediatric consultant at the Alberta Children’s Hospital in Calgary.
Benjamin Barankin, MD, is a dermatologist and the medical director and founder of the Toronto Dermatology Centre.
References
1. Eminger L. Angiokeratomas Mibelli and Fordyce. In: Heyman WR, Anderson BE, Hivnor C, Lessin S, eds. Clinical Decision Support: Dermatology. Wilmington, DE: Decision Support in Medicine; 2012. http://www.decisionsupportinmedicine.com. Accessed April 16, 2015.
2. Schiller PI, Itin PH. Angiokeratomas: an update. Dermatology. 1996;193(4): 275-282.
3. Bazin E. Naevus à pernione. In: Bazin E. Leçons Théoriques et Cliniques sur les Affections Cutanées Artificielles. Paris, France: Adrien Delahaye; 1862:437.
4. Mibelli V. Di una nuova forma di cheratosi “angiocheratoma.” G Ital Mal Ven. 1889;30:285-301.
5. Zaballos P, Daufí C, Puig S, et al. Dermoscopy of solitary angiokeratomas: a morphological study. Arch Dermatol. 2007;143(3):318-325.
6. Sadana D, Sharma YK, Dash K, Chaudhari ND, Dharwadkar AA, Dogra BB. Angiokeratoma circumscriptum in a young male. Indian J Dermatol. 2014;59(1):85-87.
7. Kandalgaonkar S, Tupsakhare S, Patil A, Agrawal G, Gabhane M, Sonune S. Solitary angiokeratoma of oral mucosa: a rare presentation. Case Rep Dent. 2013;2013:812323. doi:10.1155/2013/812323.
8. Trindade F, Torrelo A, Kutzner H, Requena L, Tellechea Ó, Colmenero I. An immunohistochemical study of angiokeratomas of children. Am J Dermatopath. 2014;36(10):796-799.
9. Imperial R, Helwig EB. Angiokeratoma: a clinicopathological study. Arch Dermatol. 1967;95(2):166-175.
10. Bechara FG, Jansen T, Wilmert M, Altmeyer P, Hoffmann K. Angiokeratoma Fordyce of the glans penis: combined treatment with erbium: YAG and 532 nm KTP (frequency doubled neodynium: YAG) laser. J Dermatol. 2004;31(11):943-945.
11. Jindal SR, Chalvade P, Jerajani HR. Late onset palmar angiokeratoma circumscriptum: an unusual presentation. Indian Dermatol Online J. 2014;5(3):320-322. doi:10.4103/2229-5178.137790.
12. Kelly B, Kelly E. Angiokeratoma corporis diffusum in a patient with no recognizable enzyme abnormalities. Arch Dermatol. 2006;142(5):615-618.