Skin Tag

Acrochordon: a soft, flesh coloured or brown, pedunculated, benign fibroepithelial polyp composed of collagen, nerve fibres and fat covered by thinned epidermis.

• Very common: found in about 40 to 60% of adults, increasing with age, and appearing in the fourth decade onward.
• Associations and causes: friction in skin folds, obesity, insulin resistance, type 2 diabetes, metabolic syndrome, dyslipidaemia, polycystic ovary syndrome, pregnancy (hormonal change), acromegaly (growth hormone excess), and a family history. Human papillomavirus types 6 and 11 have been found in some tags. Multiple tags are linked to Birt-Hogg-Dube syndrome (with fibrofolliculomas, lung cysts, pneumothorax and renal tumours).
• Tags do not become malignant, and do not themselves signal an internal cancer. The sudden eruption of many tags is a reason to check glucose and growth hormone excess.

• Three forms: small filiform papules (1 to 2 mm, often multiple, in necks and axillae), larger papules (2 to 5 mm), and large pedunculated or bag like lesions (above 1 cm, usually few, on the trunk, groin or thighs).
• Soft, smooth or wrinkled, skin coloured to brown, attached by a narrow stalk.
• Sites: neck, axillae, groin, inframammary folds, eyelids and upper trunk. They are usually asymptomatic, but may catch on clothing, jewellery and razors, and bleed.
• Twisting of the stalk can cause torsion, ischaemia and thrombosis, producing a painful, dark purple or black tag that falls off.
• Differential diagnosis: seborrhoeic keratosis, viral wart, neurofibroma (soft, buttonhole sign, with neurofibromatosis features), melanocytic naevus (papillomatous), molluscum contagiosum, fibroepithelial polyp, pigmented basal cell carcinoma, pedunculated melanoma, and fibrofolliculoma.
• Complications: irritation, bleeding, torsion, cosmetic distress, and inflammation from friction.

• Clinical. No tests are needed for a few typical tags.
• For numerous tags, check body mass index, blood pressure, fasting glucose or HbA1c, lipids, and in women with irregular periods or hirsutism, screen for polycystic ovary syndrome. Consider insulin like growth factor 1 if acromegalic features are present.
• Send any lesion that is pigmented, ulcerated, bleeding, rapidly growing, or atypical for histology. Tags removed for cosmetic reasons are normally not examined unless there is any doubt, but a pathology request is wise for any unusual specimen.
• Birt-Hogg-Dube syndrome (many fibrofolliculomas, trichodiscomas and tags, a history of pneumothorax, and a family history of renal cancer) needs genetic testing (FLCN) and renal imaging.

• Treatment is optional and cosmetic. Remove tags that are symptomatic (catching, bleeding, irritating), inflamed, thrombosed, or objected to by the patient.
• Methods (all done in clinic, with a clean technique):
  • Snip excision: for small filiform tags, cut at the base with sterile curved iris scissors. Local anaesthesia (lidocaine 1%, 0.1 to 0.5 mL injected at the base) is used for larger tags, and none is needed for tiny tags. Control bleeding with aluminium chloride 20% solution, a silver nitrate stick, or Monsel solution.
  • Cryotherapy: hold the tag with forceps and apply liquid nitrogen for 5 to 10 seconds, with a light freeze to the stalk. The tag blackens and falls off in 1 to 2 weeks. It is suitable for multiple small tags, with a risk of hypopigmentation in dark skin.
  • Electrodesiccation or hyfrecation: for small tags, with or without topical anaesthetic cream.
  • Ligation: tie the base with fine suture material or dental floss to cut the blood supply, which causes it to fall off in 3 to 7 days. It is useful for larger pedunculated tags.
  • Shave excision with cautery for broad based lesions, and carbon dioxide laser ablation for large numbers.
• Eyelid tags: do not freeze near the eye. Snip excision by a clinician trained in eyelid surgery, or referral to ophthalmology.
• Large or bulky skin folds ("skin bags"), or tags larger than 2 cm: surgical excision under local anaesthesia, with suturing.
• Avoid home removal of large, pigmented or bleeding tags. Over-the-counter freezing kits and tying bands should not be used on the eyelids, genitalia, or anywhere a diagnosis is uncertain.
• Wound care: clean daily with water, apply petroleum jelly and a plaster for 3 to 7 days. Watch for infection, which is rare.
• Address risk factors: weight reduction, control of glucose and lipids, and reduction of friction with loose clothing. New tags may appear after removal.
• Special groups:
  • Pregnancy: tags often arise or enlarge, and may resolve after delivery, so defer removal unless troublesome. Snip excision with lidocaine is acceptable.
  • Anticoagulation or bleeding tendency: cryotherapy and ligation have lower bleeding risk, or use snip excision with prolonged pressure and aluminium chloride.
  • Diabetes: treat promptly if infected, and delay in poorly controlled disease.
  • Children: rare, so look for genetic syndromes and other tumours.
• Follow up: none needed unless there is infection, recurrence or an atypical specimen. Refer to dermatology for diagnostic doubt, to oculoplastics for eyelid lesions, and to genetics for suspected Birt-Hogg-Dube syndrome.