Large patches of scalp fall off consider the following two disease possibilities. The first possibility is common psoriasis, which is mainly accompanied by scalp shedding while thicker red patches or plaques can appear on the scalp with intense itching. The cause is not clear, and may be due to genetics or immune disorders, or trauma, or smoking and other factors. In clinical treatment, you can take oral compound glycyrrhizin tablets, and compound amineptin tablets, and apply topical carboplatin application, and dinaide ointment to treat. The second may consider hair red furuncle, the etiology is not clear, may have a relationship with genetic factors and so on. In the treatment can take oral compound glycyrrhizin capsule, external use of mometasone furoate ointment application treatment.