This condition of ingrown hairs is primarily on the shaving areas of the face and neck, not the posterior scalp, and lacks the firm, keloidal papules of AKN.
This refers to a general fungal infection; it would present as a scaly patch and be confirmed by a KOH test, unlike the firm papules of the other two conditions.
This fungal infection specifically affects the beard area with inflamed pustules, a different location and etiology than the keloidal papules on the nape of the neck in AKN.