Nonscarring Alopecias: Clinical features of the most common types Patterned hair loss: - Age: puberty or older - Onset: gradual - Possible FHx - Hair thinning with or without bare patches - Distribution: men- the crown, receding hairline; women- wider midline part of the crown Telogen effluvium: - Age: mostly adults - Onset: abrupt - May be triggered by iron deficiency, thyroid imbalance, general anesthesia, postpartum, and drugs - Hair thinning, No bare patches - Distribution: generalized Alopecia areata: - Age: mostly before 20 years of age - Onset: abrupt - May have or FHx of autoimmune disease - Mostly bare patches; rarely diffuse hair thinning - Distribution: patchy or multifocal - Total alopecia in 5% of cases Tinea capitis - Age: mostly children - Onset: gradual or abrupt - Contact with animals (eg pets) - Bare patches - Distribution: any area of scalp; focal or multifocal with or without inflammation; scales Trichotillomania - Age: mostly children and adolescents - Onset: gradual or abrupt - Feeling a tension that is relieved by pulling the hair - Can be associated with other psychiatric disorders - Hair thinning, Rarely bare patches, Bizarre shaped patches with irregular borders - Distribution: frontotemporal/frontoparietal scalps #Alopecia #types #differential #diagnosis
