Microcytic anemia

Microcytic anemia
Classification and external resources
ICD-10	D50.8

Microcytic anemia (BrE: anaemia) is a generic term for any type of anemia characterized by small red blood cells. The normal mean corpuscular volume (abbreviated to MCV on full blood count results) is 76-100 fL, with smaller cells (<76 fL) described as microcytic and larger cells (>100 fL) as macrocytic.

In microcytic anemia, the red blood cells (erythrocytes) are usually also hypochromic, meaning that the red blood cells are paler than usual. This can be quantified as the mean corpuscular hemoglobin or mean cell hemoglobin (MCH), the amount of hemoglobin per cell; the normal value is 27-32 picograms (pg). Similar is the mean corpuscular hemoglobin concentration (MCHC), giving the amount of hemoglobin per volume of erythrocytes (normally about 320-360 g/L or 32-36 g/dL). Typically, therefore, anemia of this category is described as "microcytic, hypochromic anemia".

Causes

Typical causes of microcytic anemia include:

• childhood
  • iron deficiency anemia,^[1] by far the most common cause of anemia in general and of microcytic anemia in particular
  • thalassemia
• adulthood
  • iron deficiency anemia
  • sideroblastic anemia, congenital or acquired
  • anemia of chronic disease^[2] , although this more typically causes normochromic, normocytic anemia. Microcytic anemia has been discussed by Weng et al.^[2]
  • lead poisoning (rare)
  • pyridoxine deficiency

Other causes that are "typically" thought of as causing normocytic anemia or macrocytic anemia must also be considered, and the presence of two or more causes of anemia can distort the "typical" picture of each.

The Mentzer index is one tool used to identify the cause of microcytic anemias.

See also

• Hypochromic anemia

References

1. ^ Iolascon A, De Falco L, Beaumont C (January 2009). "Molecular basis of inherited microcytic anemia due to defects in iron acquisition or heme synthesis". Haematologica 94 (3): 395–408. doi:10.3324/haematol.13619. PMC 2649346. PMID 19181781. http://www.haematologica.org/cgi/pmidlookup?view=long&pmid=19181781. 
2. ^ ^{a b} Weng, CH; Chen JB, Wang J, Wu CC, Yu Y, Lin TH (2011). "Surgically Curable Non-Iron Deficiency Microcytic Anemia: Castleman's Disease.". Onkologie 34 (8-9): 456–8. doi:10.1159/000331283. PMID 21934347. http://content.karger.com/produktedb/produkte.asp?DOI=000331283&typ=pdf. 

External links

• Emedicine on chronic anemia
• FP Notebook
• American Family Physician
• Overview (vet)

↓

Anemia	Nutritional Micro-: Iron deficiency anemia (Plummer-Vinson syndrome) Macro-: Megaloblastic anemia (Pernicious anemia) Hemolytic (mostly Normo-) Hereditary enzymopathy: G6PD · glycolysis (PK, TI, HK) hemoglobinopathy: Thalassemia (alpha, beta, delta)  · Sickle-cell disease/trait · HPFH membrane: Hereditary spherocytosis (Minkowski-Chauffard syndrome) · Hereditary elliptocytosis (Southeast Asian ovalocytosis) · Hereditary stomatocytosis Acquired Autoimmune (WAHA, CAD, PCH) membrane (PNH) MAHA · TM (HUS) Drug-induced autoimmune · Drug-induced nonautoimmune Hemolytic disease of the newborn Aplastic (mostly Normo-) Hereditary: Fanconi anemia · Diamond–Blackfan anemia Acquired: PRCA · Sideroblastic anemia · Myelophthisic Blood tests MCV (Normocytic, Microcytic, Macrocytic) · MCHC (Normochromic, Hypochromic)
Other	Methemoglobinemia · Sulfhemoglobinemia · Reticulocytopenia

Coagulation/
coagulopathy

↑	Hyper- coagulability primary: Antithrombin III deficiency · Protein C deficiency/Activated protein C resistance/Protein S deficiency/Factor V Leiden · Hyperprothrombinemia acquired:Thrombocytosis (essential) · DIC (Congenital afibrinogenemia, Purpura fulminans) · autoimmune (Antiphospholipid)
↓	Hypo- coagulability Thrombocytopenia Thrombocytopenic purpura: ITP (Evans syndrome) · TM (TTP) Heparin-induced thrombocytopenia · May-Hegglin anomaly Platelet function adhesion (Bernard–Soulier syndrome) · aggregation (Glanzmann's thrombasthenia) · platelet storage pool deficiency (Hermansky–Pudlak syndrome, Gray platelet syndrome) Clotting factor Hemophilia (A/VIII, B/IX, C/XI) • Von Willebrand disease • Hypoprothrombinemia/II · XIII · Dysfibrinogenemia

M: MYL cell/phys (coag, heme, immu, gran), csfs rbmg/mogr/tumr/hist, sysi/epon, btst drug (B1/2/3+5+6), btst, trns