Sulfhemoglobinemia
Medical condition
From Wikipedia, the free encyclopedia
Sulfhemoglobinemia is a rare condition in which there is excess sulfhemoglobin (SulfHb) in the blood. The pigment is a greenish derivative of hemoglobin which cannot be converted back to normal, functional hemoglobin. It causes cyanosis even at low blood levels.
| Sulfhemoglobinemia | |
|---|---|
| Specialty | Hematology |
| Symptoms | Cyanosis, urinary tract infection and chronic constipation |
| Complications | Hypoxemia, methemoglobinemia, and hypoxia |
| Duration | 100-120 days (lifespan of red blood cells) |
| Causes | Sulfur medications such as phenacetin, metoclopramide, dapsone, phenzopyridine, and trimethoprim-sulfamethoxazole; hydrogen-sulfide-producing intestinal bacteria, such as Morganella morganii |
| Risk factors | Pulmonary arteriovenous malformation |
| Prevention | Avoidance of sulfur-containing compounds including drugs |
| Treatment | Blood transfusions |
It is a rare blood condition in which the β-pyrrole ring of the hemoglobin molecule has the ability to bind irreversibly to any substance containing a sulfur atom.[1][2] When hydrogen sulfide (H2S) (or sulfide ions) and ferrous ions combine in the heme of hemoglobin, the blood is thus incapable of transporting oxygen to the tissues.
Presentation
Symptoms include a blueish or greenish coloration of the blood (cyanosis), skin, and mucous membranes, even though a blood count test may not show any abnormalities in the blood. This discoloration is caused by greater than 5 grams per cent of deoxyhemoglobin, or 1.5 grams per cent of methemoglobin, or 0.5 grams per cent of sulfhemoglobin, all serious medical abnormalities.[citation needed]
Causes
Sulfhemoglobinemia is usually drug induced, with drugs associated with it including sulphonamides, such as sulfasalazine or sumatriptan. Another possible cause is occupational exposure to sulfur compounds.[citation needed]
It can also be caused by phenazopyridine.[3]
Diagnosis
Treatment
The condition generally resolves itself with erythrocyte (red blood cell) turnover, although blood transfusions can be necessary in extreme cases.[citation needed]