The manifestations of Iron deficiency evolve insidiously and are multi-systemic. They include
Iron deficiency causes hypochromic microcytic anaemia. The anaemia has an insidious onset and the patient may become severely anaemic before symptoms of anaemia become evident.
Iron deficiency can cause fatigue, irritability, dizziness, breathlessness, and headache. One may attribute these symptoms to anaemia but these symptoms are seen in patients with iron deficiency even in the absence of anaemia. Iron therapy has been shown to correct many of these manifestations.
Skin and Hair
Iron deficiency results in brittle nails that have longitudinal ridges. The nails become thin, brittle and become flat (platonychia) or concave (koilonychia). Hair may become thin and brittle.
Next to blood the effects of iron deficiency are most pronounced on the gastrointestinal system
- Tongue: Iron deficiency causes atrophy of the papillae of the tongue. The filiform papillae of the anterior part of the tongue are the first to be affected. The fungiform papillae of the posterior tongue atrophy later resulting in a smooth red tongue. Papillary atrophy results in soreness of the tongue. The changes reverse after about 1-2 weeks of iron therapy.
- Mouth: Iron deficiency results in angular stomatitis. This anomalies is not specific to iron deficiency may be seen in pyridoxine and riboflavin deficiency.
- Dysphagia: Iron deficiency results in the formation of webs at the junction of hypopharynx and oesophagus. These manifest as dysphagia that has an insidious onset. The patients complains of discomfort on swallowing, initially for solids, at the level of the cricoid cartilage. Mild dysphagia may be corrected by iron replenishment but dysphagia persists in most patients despite iron replenishment and dilatation may be needed. Oesophageal webs predispose to carcinoma. (See Plummer-Vinson Syndrome/Peterson-Kelly Syndrome)
- Pica: Pica is craving for non-nutritive substances like chalk, paint and ice. Pagophagia, the craving for ice is a common form of pica.
Iron deficiency impairs performance of muscles. Children with iron deficiency show irritability, are disruptive, have impaired attention span and may show scholastic impairment. Iron deficiency has also been shown to be associated with developmental delay, ischaemic stroke and raised intracranial pressure.
Effect on Immunity and Infections
Iron deficiency decreases the number of T lymphocytes and impairs phagocytosis. This however does not appear to result in an increased risk of infections.
While menstrual anomalies can be a cause of iron deficiency, they can often be a consequence of iron deficiency. Only response to treatment can tell which of the two is the case in a given patient.
Young patients who have prolonged iron deficiency may develop bone changes line haemolytic anaemia or thalassaemia because of bone marrow expansion.