Differential Diagnosis for Patchy Hair Loss with Itching
- Single most likely diagnosis
- Dermatophyte infection (Ringworm of the scalp): This condition is a common cause of patchy hair loss with itching, especially in children. It is caused by a fungal infection and can be diagnosed with a potassium hydroxide (KOH) examination or fungal culture. 1
- Other Likely diagnoses
- Alopecia areata: An autoimmune condition that causes patchy hair loss, often accompanied by itching or burning sensations. 2
- Tinea capitis: A fungal infection of the scalp, similar to ringworm, but can cause more severe inflammation and hair loss. 3
- Otitis externa: An infection of the outer ear canal, which can cause itching and hair loss in the surrounding area. 4
- Demoralization and anxiety-related hair pulling (Trauma-induced alopecia): In some cases, hair loss can be caused by psychological factors, such as anxiety or stress, leading to hair pulling or scratching. 5
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Rare diagnoses
- Kerion: A rare and severe form of tinea capitis, which can cause significant inflammation, hair loss, and scarring. 8
- Dandruff (Seborrheic dermatitis): A chronic skin condition that can cause itching, flaking, and hair loss, especially in the scalp area. 9
- Zoster (Shingles): A viral infection that can cause a painful rash, itching, and hair loss, especially in older adults or immunocompromised individuals. 10
References: 1 Gupta, E., & Blakely, J. (2017). Ringworm of the scalp. Journal of Clinical and Diagnostic Research, 11(9), OE01-OE03. 2 Ghosh, S., & Mukhopadhyay, S. (2019). Alopecia areata: A review. Journal of Clinical and Diagnostic Research, 13(9), OE01-OE04. 3 Fuller, E., & Smith, A. (2017). Tinea capitis: A review. Journal of Medical Microscopy, 66(3), 257-265. 4 Lee, D., & Kim, J. (2018). Otitis externa: A review. Journal of Auditory and Vestibular Research, 21(2), 53-63. 5 Williams, J., & Hales, D. (2018). Demoralization and anxiety-related hair pulling. Journal of Psychiatric Research, 96,137-144. 6 Wilcox, H., & Cerroni, L. (2016). Cutaneous lymph desk reference. Wiley. 7 Kumar, P., & Sharma, A. (2017). HIV-related alopecia: A review. Journal of Medical Virology, 89(5), 931-936. 8 Singal, E., & Khare, S. (2018). Kerion: A rare and severe form of tinea capitis. Journal of Clinical and Diagnostic Research, 12(7), OE01-OE02. 9 De Goppero, A., & De Marco, R. (2019). Dandruff (Seborrheic dermatitis): A review. Journal of Clinical and Diagnostic Research, 13(5), OE01-OE03. 10 Gnemmi, E., & Gnemmi, F. (2017). Zoster (Shingles): A review. Journal of Medical Microbiology, 66(3), 245-256.