Hi. Thanks for writing in to HCM. A dermatologic consultation is warranted indeed in case of severe dandruff whether it is just dandruff (Seborrheic dermatitis) or is it something else....e.g scalp psoriasis also presents as dandruff initially but it is not controlled effectively by an OTC anti-dandruff shampoo. Their are medicated shampoos which only a dermatologist can prescribe you like the ones containing coal tar/salicylic acid/fluticasone in shampoo base. You may be asked to apply steroid based lotions, solutions, foams or gels by your dermatologist for faster control. Avoid using hair oil. take care regards.