🗂 總目錄 ｜ 📖 英文原文（本篇） ｜ 📝 完整翻譯 ｜ ⭐ 精華筆記

Angiokeratoma

Angiokeratoma

Clinical features

Angiokeratoma represents ectasia of superficial blood vessels associated with secondary epidermal changes, especially acanthosis and hyperkeratosis.1 Five variants have been described.
• Angiokeratoma of Fordyce: this develops mainly on the scrotum of elderly men as single or multiple, blue or red papules.2 Involvement of the penis may also be seen and is sometimes prominent.3 Similar lesions can occur on the vulva of young women.4 Unilateral lesions are very rare.5
• Angiokeratoma of Mibelli: this presents as warty papules on the distal limbs (especially fingers and toes) of children and adolescents, showing a predilection for females.6
• Angiokeratoma circumscriptum: this is very rare and presents as grouped papules or a plaque with predilection for the upper and lower limbs of children, with a predilection for females.7 A case associated with injury and one in a systematized band-like pattern suggesting mosaicism have been documented.8,9
• Angiokeratoma corporis diffusum: this is characterized by widespread clusters of red papules in a symmetrical distribution, especially in the ‘bathing-trunk’ area.1,10 Exceptionally, lesions are seen on the palms and soles.11 It is usually, but not exclusively, associated with Anderson-Fabry disease, an X-linked genetic disorder that results from a deficiency of the lysosomal enzyme α-galactosidase A. Treatment with the enzyme can induce regression of the angiokeratomas.12 Patients with other enzymatic deficiencies including L-fucosidase, β-mannosidase, α-N-acetylgalactosaminidase, neuraminidase and β-galactosidase deficiency and even individuals with no detectable abnormalities, exceptionally in a familial setting, can show identical lesions.13–21 Multiple hemangiomas without angiokeratomas in a female carrier of Fabry disease have been documented.22
• Solitary and multiple angiokeratomas: these have a wide age range and anatomical distribution and preferentially affect the lower limbs.1 Most lesions are solitary. Multiple lesions have been reported in a zosteriform distribution.23 Distribution along Blaschko lines can be seen.24 Lesions can develop as a consequence of radiotherapy and angiokeratoma-like lesions can be seen in lichen sclerosus.25–27 Injection of etanercept induced angiokeratomas in a single patient.28 Associations with epidermal nevus, vascular malformations, nevus lipomatosus superficialis have also been documented.29–32

Histologic features Histology shows dilated small vascular channels in the papillary dermis.