Erysipelas

Part of a spectrum of infection.

1. Impetigo - see http://adultemergencymedicine.blogspot.com/2018/08/rashes-impetigo.html 

2. Erysipelas is a superficial cellulitis, with similar risk factors. It looks a lot worse than cellulitis with ruptured bullae and vivid bright red erythema. Almost all erysipelas is caused by group A beta haemolytic strep. It can recur due to persistence of risk factors and lymphatic drainage. Complications can include abscesses, gangrene, chronic leg swelling

Signs and symptoms are normally abrupt, affecting predominantly the lower limb and face. It has a sharp raised border, and is bright red and swollen. The swelling may lead to dimpling, blistering, and even necrosis.

3. Cellulitis
Cellulitis is very rarely bilateral. 35-50% of patients will have a leukocytosis, 60-92% will have an elevated ESR, and 75-95% will have an elevated CRP.  Blood cultures are unlikely to be helpful.
Orals are very bioavailable so most of the time are just as good as IVs.

Often caused by strep and staph. Atypicals are common: Cat bites can have pasteurella, sea water Vibrio vulnificus, fresh water Aeromonas hydrophila, fish farms Streptococcus iniae. These atypicals can cause a rapidly progressive cellulitis.

Fascitis necrotizante

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Class I: No signs of systemic toxicity or co-morbidities. Can be managed on POs.
Class II: 2 or more SIRS, but no organ dysfunction, or have a co-morbidity. May need IV outpatient management.
Class III: Sepsis and organ dysfunction, or unstable co-morbidities normally require admission.
Class IV: Severe life threatening infection.

4. Necrotising Fascitis

https://www.dermnetnz.org/topics/erysipelas/
https://journalfeed.org/article-a-day/2018/lrinec-score-physical-exam-or-imaging-for-necrotizing-infection
http://www.emdocs.net/cellulitis-mimics-ed-considerations/
https://first10em.com/cellulitis-antibiotics/
https://www.rcemlearning.co.uk/modules/cellulitis-and-other-skin-infections/
https://journalfeed.org/article-a-day/2018/is-a-blood-culture-needed-in-cellulitis
https://www.rcemlearning.co.uk/references/cellulitis/
http://www.tamingthesru.com/blog/2018/9/3/necrotizing-fasciitis-and-the-spectrum-of-soft-tissue-infections

Bleeding in Pregnancy

<23 Weeks - Early Pregnancy 
This has been covered here: https://www.rcemlearning.co.uk/foamed/induction-bleeding-in-early-pregnancy/

Later Pregnancy
https://www.rcemlearning.co.uk/modules/bleeding-in-pregnancy/

Antepartum Haemorrhage
>24 weeks gestation
Placenta praevia - stage depends how much of the os is covered by the placenta. Bright red and painless bleeding.
Placental abruption - complete or partial separation of the placenta. Causes lots of bleeding which may be concealed. Normally associated with continuous abdominal pain.
Vasa praevia - the fetal blood vessels run everywhere, not protected by the placenta. They may run over the cervix. High perinatal mortality - easy to rupture the fetal blood vessels. Can cause painless bleeding.
AntiD may be needed after a potentially sensitising event.

Hopefully all of these will be identified by screening, and hopefully these patients will present to the maternity assessment unit, not the ED!

PostPartum Haemorrhage
Primary PPH - in first 24hours. Secondary PPH - up to six weeks. Again, hopefully these patients will present to MAU not ED.

In pregnancy, problems are the 4Ts
 Tone, trauma, tissue, thrombin.
 Tone: uterine massage, bimanual compression, catheterise, give syntrometrin

Bleeding should slowly stop after a 12 weeks. It's often significantly less after the first few hours, and should change from  bright red to brown (lochia).
The commonest cause is endometritis. There may be retained products - start IVs, get an USS. If there's no RPOC, there could still be endometritis. The uterus in endometritis will remain palpable after 14days after delivery.  Endometritis is a clinical diagnosis.
I think bleeding persistently after delivery needs to see O&G.
Bleeding that stops and starts again is probably "new" bleeding.


https://www.bmj.com/content/358/bmj.j3875?sso=
http://www.emdocs.net/postpartum-endometritis-ed-setting-presentation-evaluation-management/

B12 Anaemia

B12 deficiency, cobalamin deficiency or pernicious anaemia is also knon as Biermer's anaemia, Addison's or Addison-Biermer anaemia. It's one of the megaloblastic anaemias.

Pathophysiology
Normally, B12 is absorbed through the ileum with the help of intinsic factor which is secreted by the parietal cells.
Various things can stop this happening - antibiodies to parietal cells, like in atrophic gastritis, antibodies to intrinsic factor like in pernicious anaemia, lack of a terminal ileum, or disease of the ileum - like Crohn's disease, and reduced b12 intake.
It takes a while for the disease to become apparent as there's 3-5 years worth of reserves in the liver.
Lack of B12 means that DNA replication is slow, so cells divide less but grow bigger. This gives you your macrocytic or megaloblastic anaemia.
Lack of B12 means the conversion of homocysteine to methionine is reduced, so there are high levels of homocysteine - causing things like atherosclerosis, thromboembolism and osteoporosis.
More importantly, B12 is a cofactor in the conversion of methylmalonic acid into succinyl CoA. Without this, the dorsal and lateral spinal columns are demyelinated, through an unknown mechanism, so you get neurological symptoms.

Investigation
FBC will show macrocytic anaemia, and maybe neutropaenia and thrombocytopenia.
A blood film will show anisocytosis and poikilocytosis.
Bilirubin may be increased because of haemolysis.
Then you can look for autoantibiodies, and maybe an absorption test like the Schilling test.


Symptoms
Symmetrical, legs > arms
Ataxia
Loss of position sense
Loss of vibration sense

Low grade pyrexia, weight loss, diarrhoea, jaundice due to haemolysis, pallor due to anaemia, premature greying of the hair.

Treatment
If B12 levels are low, then patients need intramuscular B12 and a haematology referal. If there is neurological involvement, 5 - 6 loading doses of 1000mcg, followed by maintainence of 1000mcg every three months.
If B12 levels are borderline, then oral B12 may have a reponse and be diagnostic.
Patients often feel better within 24hours of starting treatment.
If patients are asymptomatic, there is debate about their treatment- monitoring seems preferred.

B12 is naturally found in animal products - fish, meet, eggs, milk. It's not generally present in plant foods, but is in fortified cereals. It's worth mentioning that pabrinex doesn't contain B12!

http://calgaryguide.ucalgary.ca/vitamin-b12-deficiency/
https://www.gpnotebook.co.uk/simplepage.cfm?ID=1288699922&linkID=26150&cook=no