This accumulation depletes the other types of folate required for purine and thymidylate synthesis, which are required for the synthesis of DNA. Inhibition of DNA replication in maturing red blood cells results in the formation of large, fragile megaloblastic erythrocytes. The neurological aspects of the disease are thought to arise from the accumulation of methylmalonyl- CoA due to the requirement of B12 as a cofactor to the enzyme methylmalonyl-CoA mutase. Diagnosis
Pernicious anemia is thought mainly to be an autoimmune disorder that attacks the gastric parietal cells that produce intrinsic factor resulting in impaired absorption of B12. However, pernicious anemia may also have a genetic component, potentially running in families. Pernicious anemia may be suspected when a blood smear shows large, brittle, immature, erythrocytes, known as megaloblasts. To make a diagnosis a full blood count, and blood smear, with the following tests included is needed:
A complete blood count and blood smear evaluates the mean corpuscular volume (MCV) and the mean corpuscular hemoglobin concentration (MCHC) to demonstrate  megaloblastic anemia. PA is identified with a high MCV (macrocytic anemia) and a normal MCHC (normochromic anemia). Ovalocytes are also typically seen on the blood smear, and a pathognomonic feature of megaloblastic anemias (which include PA and others) is hypersegmented neutrophils. Vitamin B12 serum levels are used to detect its deficiency, but do not distinguish its causes. Vitamin B12 levels can be falsely high or low and data for sensitivity and specificity vary widely.
The CIWA has also been shortened (now called the CIWA-Ar), while retaining its validity and reliability, to help assess patients more efficiently due to the life-threatening nature of alcohol withdrawal.Other conditions that may present similarly include benzodiazepine withdrawal syndrome (a condition also mainly caused by GABAA receptor adaptation). Treatment
Benzodiazepines  are effective for the management of symptoms as well as the prevention of seizures. Certain vitamins are also an important part of the management of alcohol withdrawal syndrome. In those with severe symptoms inpatient care is often required. In those with lesser symptoms treatment at home may be possible with daily visits with a health care provider. Benzodiazepines
Benzodiazepines are the most commonly used medication for the treatment of alcohol withdrawal and are generally safe and effective in suppressing symptoms of alcohol withdrawal. This class of medication is generally effective in symptoms control, but need to be used carefully. Although benzodiazepines have a long history of successfully treating and preventing withdrawal, there is no consensus on the ideal one to use. The most commonly used agents are long-acting benzodiazepines, such as chlordiazepoxide and diazepam. These are believed to be superior to other benzodiazepines for treatment of delirium and allow for longer periods between doses. However, benzodiazepines with intermediate half-lives like lorazepam may be safer in people with liver problems. Benzodiazepines showed a protective benefit against alcohol withdrawal symptoms, in particular seizure, compared to other common methods of treatment.The primary debate between use of long-acting benzodiazepines and short-acting is that of ease of use.