Prof. Sebastian L Johnston is a distinguished medical specialist in respiratory medicine and allergy. He graduated from the University of London in 1982 and has since built a reputable career in his field. Prof. Johnston holds the position of Prof. of Respiratory Medicine & Allergy at the National Heart and Lung Institute, Imperial College London. Additionally, he serves as a Consultant Physician in Respiratory Medicine & Allergy at St Mary's Hospital, part of the Imperial Healthcare NHS Trust in London.

Prof. Johnston is the Director of the Asthma UK Centre in Allergic Mechanisms of Asthma and holds the title of Asthma UK Clinical Professor. His clinical interests are primarily focused on the treatment of asthma, allergies, and general respiratory medicine.

Throughout his career, Prof. Johnston has developed extensive expertise in a variety of conditions and treatments. He specialises in general respiratory medicine, asthma, chronic obstructive pulmonary disease (COPD), and allergies, including food allergies, hay fever, and urticaria. He is also proficient in sub-lingual allergen immunotherapy, a treatment method for allergies.

Prof. Johnston has been with Imperial College London and St Mary's Hospital since his appointment in 1982. His dedication to patient care and his contributions to medical research have made him a leading figure in his field.