L72.12 Trichodermal cyst

Name of the Condition

• Trichodermal cyst

Summary

Trichodermal cysts are non-cancerous growths that form beneath the skin, typically filled with keratin or other cellular debris. They are common and can appear anywhere on the body, though they often occur on the scalp, face, neck, or trunk.

Causes

These cysts develop when hair follicles or skin glands become blocked, leading to a buildup of keratin or other substances. The exact cause is not always clear, but they may result from trauma, inflammation, or natural skin cell turnover.

Risk Factors

• Oily skin or acne
• A history of previous cysts
• Skin trauma or injury
• Genetic predisposition in some cases

Symptoms

• A small, round bump under the skin
• Usually painless but may become red, swollen, or tender if infected
• May have a visible blackhead or opening at the surface

Diagnosis

Diagnosis is typically made through a physical examination. In some cases, a biopsy or imaging may be used to confirm the diagnosis, especially if the cyst is atypical or symptomatic.

Treatment Options

• Observation: Many cysts resolve without intervention.
• Incision and drainage: Used for painful or infected cysts.
• Surgical removal: Complete excision to prevent recurrence.
• Antibiotics: Prescribed if infection is present.

Prognosis and Follow-Up

The condition is benign with no long-term health risks. Recurrence is possible after incomplete removal. Follow-up may be recommended if symptoms worsen or if the cyst recurs.

Complications

• Infection, leading to pain, redness, or pus
• Scarring from surgical removal
• Rarely, rupture or inflammation causing discomfort

Lifestyle & Prevention

• Keep the skin clean to reduce infection risk.
• Avoid squeezing or picking at cysts.
• Protect the skin from trauma or injury.

When to Seek Professional Help

Seek care if the cyst becomes painful, red, swollen, or shows signs of infection. Also, consult a provider if the cyst grows rapidly, changes appearance, or recurs after removal.

Tips for Medical Coders

Use L72.12 for trichodermal cysts. Document the location, size, and any associated symptoms (e.g., infection) to support coding accuracy. Ensure differentiation from other follicular cysts when applicable.