How many patients who are allergic to peanuts have asthma?
allergic to peanuts refers to allergies.DESCRIPTION = 'Allergy to peanuts'; asthma refers to conditions.DESCRIPTION = 'Asthma';
SELECT COUNT(DISTINCT T2.patient) FROM conditions AS T1 INNER JOIN patients AS T2 ON T1.PATIENT = T2.patient INNER JOIN allergies AS T3 ON T2.patient = T3.PATIENT WHERE T1.DESCRIPTION = 'Asthma' AND T3.DESCRIPTION = 'Allergy to peanuts'