Any age can develop the disease, but it is most commonly seen between six months and two years old, with a relatively slow onset. Generally, there is a gradual pallor of the skin and mucous membranes, most notably in the eyes, lips, oral mucosa, and nail beds. Affected children tend to be fatigued and less active, and older children may experience symptoms such as dizziness and darkening before the eyes. Physical examination may reveal enlargement of the liver, spleen, and lymph nodes; the more severe the anemia, the more pronounced the enlargement. Anemia can lead to a decreased appetite, and in some cases, pica, such as a craving to eat non-food items like soil or walls, may occur. Symptoms may also include vomiting, diarrhea, glossitis, and stomatitis. There is a general listlessness, lack of concentration, impaired memory, and intelligence that may be lower than peers of the same age. Iron deficiency anemia can also lead to decreased cellular immune function, making infections more likely.