A medical triad is a group of three signs or symptoms, the result of injury to three organs, which characterise a specific medical condition.
The appearance of all three signs conjoined together in another patient, points to that the patient has the same medical condition, or diagnosis.
A medical tetrad is a group of four, while a pentad is a group of five.
Eczema (Atopic Dermatitis), Allergic Rhinitis, bronchitis || Atopy or Atopic Triad