Upper respiratory allergies and inflammation and swelling of the adenoids, the tissue at the back of the nose, can cause poor fluid drainage from the middle ear to the external ear and therefore cause a blockage in the Eustachian tube. Excess fluid can lead to middle ear congestion.
1 Black skin and Asian skin have thicker and more compact dermis than white skin. This is also why blacks and Asians have fewer facial wrinkles than whites. 2  Black skin has more casual lipids and more moisture in the stratum corneum than white skin.  Black skin has 50% lower ceramides than white or Hispanic skin.
For us, a black american is an american, exactly as a white one. A person with american native look, is southamerican/latino if he speaks with any of the many south american accents, or spanish if he speaks with one of the many spanish accent. Same happens with white people. A black with perfect spanish accent is spanish. A unusually darker one, or whatever, but spanish.