It appears to be alopecia areata, which is associated with sudden loss of hair in well defined patches . Since it’s a single patch localised treatment with topical medication can restore here growth. It may take 3months at least.

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Hello. It doesn't look too dangerous. It is looking like alopecia areata which is a small patch of loss of hair. It is not of major concern. It requires some ointments to be applied after which the hair will come back completely in 2 or 3 months. However, that small pustule needs to looked at directly. It is not an emergency though.