- Tinea capitis – “ringworm”, actually fungal. Scalp abnormal.
- Telogen effluvium – lots of hair shed all at the same time following some sort of trigger esp birth (both baby and mother can be affected!), infection. Trigger usually 2-3 months preceding. Clumps or general thinning.
- Alopecia areata
Exclamation mark hairs (thin proximally, at scalp, normal distally) suggest alopecia areata, but may be seen in trichotillomania, so not very predictive.
Pull test – gentle traction on about 20 hairs in 3 different locations. Positive if more than 5 hairs extracted – suggests active alopecia areata. You may miss dormant alopecia areata, but in that case hair regrowth should occur anyway.