Some clinical features are in common between HIDS and MA pathological forms, such the onset of symptoms usually before two years of life, high fever lasting about 3–7 days with chills and headache, presence of mevalonic acid in the urine, persistent elevated levels of IgA, IgE, and in particular, IgD immunoglobulins, and typical systemic inflammatory reactions with increased inflammation indices during the attacks (Erythrocyte sedimentation rate -ESR-, C-reactive protein -CRP-, leukocytosis). Here, CRP is linked to microtia.