We present a three-year-old female who was diagnosed with congenital methemoglobinemia when she presented with peri-oral cyanosis and profound oxygen desaturation in the 20-30% range. [cureus.com]

It transpired that the abnormal skin color had been present since infancy. [acutecaretesting.org]

Benzocaine is present in many over-the-counter medications, but the topical sprays containing the anesthetic benzocaine cause most of the severe cases. [medicalnewstoday.com]

See Clues on the Skin: Acute Poisonings, a Critical Images slideshow, to help diagnose patients based on their dermatologic presentations. [emedicine.medscape.com]

She had presented at 2 years of age with anemia and splenomegaly, and later the diagnosis of HbE β thalassemia was established. [ashpublications.org]

• Cough

  A month later she presented with a fever/cough and decreased oral intake. [cureus.com]

• Nausea

  These can include: headache shortness of breath nausea rapid heart rate fatigue and lethargy confusion or stupor loss of consciousness Methemoglobinemia can be congenital, which means you’re born with the condition. [healthline.com]

• Strabismus

  ] Type II – Widespread deficiency of the enzyme occurs in various tissues, including erythrocytes, liver, fibroblasts, and brain; it is associated with severe CNS symptoms, including encephalopathy, microcephaly, hypertonia, athetosis, opisthotonos, strabismus [emedicine.medscape.com]

• Suggestibility

  Want to suggest a symptom? Please send suggestions to RareGuru! [rareguru.com]

  It is also important to note that the failure of 100% oxygen to correct cyanosis is highly suggestive of methemoglobinemia. [cureus.com]

  The consistently dark color of arterial blood suggested a diagnosis of methemoglobinemia, which was confirmed with the finding that the methemoglobin level was 40 %. [acutecaretesting.org]

  The results of these studies suggest that, with respect to hypoxia recognition, humans are able to compensate for ascorbate deficiency in the same way as the murine model. [ashpublications.org]

  Useful For Suggests clinical disorders or settings where the test may be helpful Diagnosis of methemoglobinemia and sulfhemoglobinemia and possible hereditary (congenital) causes Differentiation of methemoglobinemia and sulfhemoglobinemia from other causes [mayocliniclabs.com]

• Lethargy

  Other associated symptoms can include headache, shortness of breath, fatigue, lethargy, deterioration of mental functioning, loss of consciousness, or stupor. [medicinenet.com]

  These can include: headache shortness of breath nausea rapid heart rate fatigue and lethargy confusion or stupor loss of consciousness Methemoglobinemia can be congenital, which means you’re born with the condition. [healthline.com]

(See Workup.) The most important aspects of the management of methemoglobinemia are recognition of the condition and prompt initiation of treatment, when indicated. [emedicine.medscape.com]

People who acquire methemoglobinemia from medications can completely recover with proper treatment. There is no way to prevent genetic types of methemoglobinemia. [healthline.com]

The most important aspects of the management of methemoglobinemia are recognition of the condition and prompt initiation of treatment, when indicated. For mild asymptomatic cases, treatment is purely for cosmetic or psychological reasons. [emedicine.medscape.com]

Most cases will not even require treatment. [medicalnewstoday.com]

As stated in international guidelines, however, treatments should be of short duration and not exceed three months. [bmj.com]

Table 2 Further biochemical and related analyses of the propositus, including, in some cases, data obtained before and after treatment with vitamin C Variable (units), normal range Treatment period Ascorbate (nmol/mL), 28-84 Met Hb (%), 0.1-0.6 P50 (mm [ashpublications.org]

Prognosis The prognosis of mild cases of methemoglobinemia is very favorable. In severe cases, the prognosis is determined by the degree of anoxic end-organ damage. [emedicine.medscape.com]

Methemoglobinemia: etiology, pharmacology, and clinical management. Ann Emerg Med. 1999 Nov. 34(5):646-56. [QxMD MEDLINE Link]. McQueen CA, ed. Comprehensive Toxicology. 3rd ed. Amsterdam, Netherlands: Elsevier; 2017. Vol 12: Curry S. [emedicine.medscape.com]

The epidemiology of long-term benzodiazepine use. Int Rev Psychiatry2005;17:189-97. ↵ Egan M, Moride Y, Wolfson C, Monette J. Long-term continuous use of benzodiazepines by older adults in Quebec: prevalence, incidence and risk factors. [bmj.com]

A few cases of methemoglobinemia have been reported in patients with COVID-19 with underlying G6PD deficiency, although no precipitating drugs were identified. [57, 58] Epidemiology United States statistics Hereditary methemoglobinemia is rare. [emedicine.medscape.com]

Notably, the pathophysiology of congenital methemoglobinemia is unrelated to acquired methemoglobinemia, which occurs in response to toxin exposure [4]. [cureus.com]

Biological plausibility The deleterious effects of benzodiazepines on memory are well documented.22 23 No univocal pathophysiological mechanism, however, can be reasonably advanced to explain an increased risk of dementia. [bmj.com]

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test Methemoglobin: Methemoglobin forms when the hemoglobin (Hb) molecule iron is in the ferric (Fe3[+]) form instead of the functional [mayocliniclabs.com]

The presence of anemia and cyanosis despite oxygen treatment results from both of these effects. [6, 7] (See Pathophysiology and Etiology.) Methemoglobinemia occurs when red blood cells (RBCs) contain methemoglobin at levels higher than 1%. [emedicine.medscape.com]

Pathophysiology of beta thalassemia., Disorders of Hemoglobin, 2001 1st Ed Cambridge Cambridge University Press (pg. 233 - 251 ) 34,. [ashpublications.org]

Can it be prevented? Congenital MetHb cannot be prevented. People with a family history of the blood disorder are advised to request genetic counseling from a healthcare professional before starting a family. [medicalnewstoday.com]

There is no way to prevent genetic types of methemoglobinemia. [healthline.com]

Brief Summary: The purpose of this two-centre pilot research study is to establish the feasibility of conducting a full trial that seeks to determine if a cardiac anesthesia policy that uses alternatives to benzodiazepine medications is better at preventing [clinicaltrials.gov]

Wounds were treated with mafenide-acetate dressings to prevent infection. [acutecaretesting.org]

Curcumin could prevent methemoglobinemia induced by dapsone in rats. Food Chem Toxicol. 2011 Jul. 49(7):1638-41. [QxMD MEDLINE Link]. Note chocolate brown color of methemoglobinemia. [emedicine.medscape.com]