Differential Diagnosis for Sudden Hair Loss of Facial Hair
- The patient presents with a 1cm area of sudden hair loss of facial hair with no visible rash underneath.
Single most likely diagnosis
- Alopecia areata: This is an autoimmune condition that causes patchy hair loss, often on the scalp, but can also occur on the face. The sudden onset and localized nature of the hair loss make this a likely diagnosis.
Other Likely diagnoses
- Trauma or traction: Hair loss can occur due to physical trauma or traction on the hair follicles, such as from shaving or pulling on the hair.
- Infection (e.g. folliculitis): Although there is no visible rash, an underlying infection could be causing the hair loss.
- Demoralization or psychological stress: Stress and psychological factors can contribute to hair loss, including conditions like trichotillomania (compulsive hair pulling).
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Syphilis: This is a sexually transmitted infection that can cause hair loss, among other symptoms. It's essential to consider this diagnosis due to its potential severity and the need for prompt treatment.
- Metastatic disease or systemic cancer: In rare cases, hair loss can be a symptom of an underlying cancer. Although unlikely, this diagnosis should not be missed due to its potential severity.
Rare diagnoses
- Autoimmune disorders (e.g. lupus, dermatomyarditis): These conditions can cause hair loss, but are relatively rare and would typically be accompanied by other symptoms.
- Congenital conditions (e.g. congenital alopecia): These conditions are rare and would typically be present from birth.
- Helmithic infections (e.e. zoonotic infections): Certain infections caused by parasites can lead to hair loss, but these are relatively rare and would typically be accompanied by other symptoms.