Pilar Cyst (Trichilemmal Cyst) Clinical Presentation
- Author: Anne Elizabeth Laumann, MBChB, MRCP(UK), FAAD; Chief Editor: William D James, MD more...
History
- A family history may be present because the condition can have an autosomal dominant pattern of inheritance.[4]
- Pilar cysts may be tender or painful if they have ruptured or become infected.
Physical
- Pilar cysts manifest as smooth, mobile, asymptomatic swellings, often in the scalp. Overlying hair loss may be noted.[3]
- Unlike epidermoid cysts, no punctum is seen.
- Multiple cysts may be present.
- If they are inflamed, they may be tender, red, or both.
- The contents occasionally extrude to form a soft, cutaneous horn.
- The wall of a marsupialized cyst may fuse with the overlying epidermis to form a crypt. This may occasionally discharge its contents and then apparently spontaneously heal.
Causes
- If the cysts are familial, the inheritance pattern is autosomal dominant. Despite attempts at gene mapping, a specific disease locus and the responsible genes are not known.[11]
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