A lump under the skin can be concerning, especially if it becomes red, swollen, or painful. One possible cause is an epidermoid cyst, a usually harmless lump that can develop on the back, neck, or face. However, not every skin lump is a cyst.

What Causes Skin Cysts?

Epidermoid cysts form when skin cells become trapped beneath the surface, creating a sac filled with keratin, a protein found in skin and hair. Many grow slowly and remain painless, but some may become inflamed or rupture.

Warning Signs to Watch For

A cyst may become tender, swollen, warm, or red. Spreading redness, worsening pain, fever, or chills may indicate an infection and require prompt medical attention.

How Should You Care for a Skin Cyst?

Avoid squeezing, cutting, or puncturing a cyst yourself. Doing so can worsen inflammation, introduce bacteria, and cause scarring. Keep the area clean and seek medical advice if the lump becomes painful, grows, or changes.

When Should You See a Doctor?

A healthcare professional can examine the lump and determine the appropriate treatment. Some cysts need no treatment, while others may require drainage or removal.

The Bottom Line: Most epidermoid cysts are harmless, but a lump’s appearance alone cannot confirm its cause. Have any growing, persistent, painful, or changing lump checked by a healthcare professional.

Medical Disclaimer: This article is for educational purposes only and does not replace professional medical advice.