Monday, July 24, 2017

Steven-Johnson syndrome (SJS) / Toxic epidermal necrolysis (TEN) -Part 1

Hello! :)

TOXIC EPIDERMAL NECROLYSIS

-A severe form of adverse cutaneous drug reaction
-Idiosyncratic reaction
-Immunologically Mediated
- Fever and mucocutaneous lesions
-Epidermal sloughing


CLASSIFICATION

1. SJS= <10% BSA detachment
2. OVERLAPPING SJS/TEN= 10-30% detachment
3. TEN = >30% detachment

EPIDEMIOLOGY

-Both are rare but occur as a medical emergency.
-Incidence of SJS 1-7 Cases per million.
-SJS > TEN by 3: 1
-TEN tend to be older
-Worldwide distribution
-HIV positive cases have increased incidence.


ETIOLOGIES

-Drugs being the most common cause
-Infection (viral e.g. HSV, bacterial, fungi)
-Vaccination
-systemic disease (lupus)
-Physical agents (UV light, radiation)
-Idiopathic 25%

Drugs that result in this are:-

-Antibiotics = sulfonamides > penicillin > cephalosporin
-Anti-gout: allopurinol
-Anti-epileptics; carbamazepine, Dilantin
-Anti-psychotics
-Analgesic including NSAIDS


RISK FACTORS:

GENETIC SUSCEPTIBILITY:-
-HLA-B*1502 associated with greater risk with carbamazepine use in southeastern Asians.
-HLA-B*5801 confers risk with allopurinol associated reactions.
-HLA-B*44 Caucasians

HIV:-
-Slow acetylators so results in prolonged exposure to medications.
-Immune dysregulation
-Other infections
-40 Fold increased risk of SJS/TEN with cotrimoxazole (Remember! It is used as a prophylactic drug in HIV patients.)

CLINICAL PRESENTATION:-
-Drug exposure 1-3 weeks prior to onset of symptoms
-PRODROME=fever, flu-like, 1-3 days
-symmetrical lesion distribution
-starts on face and trunk before spreading
-skin blistering with sloughing for 2-3 days progressively then stabilizes
-Erythroderma
-Facial edema
-Skin pain- burning
-Palpable purpura
-Skin necrosis (Nikolsky sign)
-Blisters or epidermal detachment
-SJS tragetoid, TEN target lesions atypical
-Mucous membrane erosions or crusting
-tongue swelling
-conjuctival irritation
-Dysuria
-GI bleed
-Pulmonary bleed

LABORATORY FINDINGS

-Anemia
-Lymphopenia
-Neutropenia (poor prognosis)
-Elevated transaminases
-Cultures, If infected
-Skin biopsy-Rule out other conditions
-BUN/CR ratio
-Serum electrolytes

PATHOGENESIS

-not well understood
-Suspected immunologic
1. GRANULYSIN: Cytolytic protein from cytotoxic T-cell and NK - cells
(Highly expressed in SJS /TEN patients)
2. DEATH RECEPTOR CD95 (fas): Elevated fas ligand leading to apoptosis
3. Perforin, TNF-alpha and granzymes-B in higher concentration, associated with NON-APOPTOTIC death.

HISTOLOGY
-Early perivascular inflammation of T-lymphocytes, primarily CD8
-Monocytes infiltration
-Lymphocytes surrounding basal keratinocytes
-Subepidermal vesiculation
-Full thickness necrosis
-Increased adhesion molecules: VCAM, ICAM

EVALUATION AND DIAGNOSIS
-Clinical diagnosis on the basis on exclusion
-prior drug history or illness+fever+skin lesions with sloughing

DIFFERENTIAL DIAGNOSIS
-toxic shock syndrome (staphylococcus and streptococcus)
-Scalded skin syndrome (staphylococcus)
-Phototoxic eruptions (Sun exposure areas and known medications)
-Paraneoplastic pemphigus (Lymphoma)
-Erythematous drug eruptions (Lack mucosal involvement)
-Drug hypersensitivity syndrome /DRESS/DIHS (eosinophilia)
-Acute generalized exanthematous pustulosis (AGEP) (lack of pain and noted pustules)
-Toxic skin reaction (chemical irritant)
-Toxic erythema (Intoxication)
-Kawasaki's (diagnostic criteria)


EMM (ERYTHEMA MULTIFORME):

-targeted papules and plaques
-Acrally distributed
-Fever mild
-Significant skin detachment uncommon
-Histology: inflammation EMM>SJS

TREATMENT:-

-Immediate removal of possible triggers (especially drugs with longer half-life)

-SUPPORTIVE CARE
 - Wound care: burn unit with improved outcomes
 *avoid silver sulfadizine (Sulfonamide associated with SJS)
 -Fluid and electrolyte management (RL or NS)
 -Pain control (Local anesthetic cream)
 -Temperature regulation: caloric expenditure 
 -Monitor for infection: pseudomonas
 -Nutrition (High protein diet, Banana) (I will discuss it in next post)
 -Ocular care (Important)

 You can also refer this link 

That's all for today.
I will discuss tomorrow the case we have seen in the emergency ward on the same. And also the treatment aspect. 

-Upasana Y. :)




Myopathies series - Part 4

Hello! :)

In previous post, I left you with a question

How do we identify the site and cause of lesion?

Important points in history and neurological examination that is suggestive of myopathy are:-

1. MUSCLE WEAKNESS

According to Taber's medical dictionary, Lacking physical strength or vigor; infirm especially as compared with what would be the normal or usual for that individual.

Most muscle diseases produces symmetrical weakness of the large muscles of the girdles and trunk.

A) HIP GIRDLE (MOST COMMONLY AFFECTED)
- Difficulty in getting up from squatting position or from low chair,
-Inability to climb stairs,
-Waddling gait.

B) UPPER GIRDLE WEAKNESS
- Difficulty in hanging clothes on a cloth line
-Difficulty in taking down item from high shelves.

C) TRUNK WEAKNESS
-Difficulty in turning in bed and getting up from recumbent position.

D) NECK MUSCLE WEAKNESS 
-Inability to control neck while in a vehicle as it rapidly accelerates and decelerates.
-neck pain and stiffness.

E) CRANIAL MUSCULATURE WEAKNESS
1. FACIAL WEAKNESS:-
-Inability to close eyes fully.
-Difficulty in drinking with a straw.

2. OCCULAR WEAKNESS:- (I will explain this below in bit detail )
-ptosis
-extraoccular movement weakness are seen.

F) DISTAL MUSCULATURE WEAKNESS
-Difficulty in opening lids of jar
-turning keys in keyholes

-tend to trip on uneven ground with repeated falls.




2. GAIT

3. FATIGUE

According to Taber's medical dictionary, the condition of an organ or tissue in which its response to stimulation is reduced or lost as a result of over activity.

Abnormal fatigability after exercise can result from certain metabolic and mitochondrial myopathies.

And as I have already discussed the importance of duration and intensity of exercise that provokes fatigue. It helps to distinguish metabolic myopathies.


4. MYALGIA
-Episodic= metabolic myopathies

-Constant=inflammatory muscle disorders


5. OCULOBULBAR WEAKNESS

6. SENSORY SYSTEM = NORMAL 

7. MYOGLOBINURIA 

- Why? As caused by the excessive release of myoglobin from muscles during periods of rapid muscles destruction (rhabdomyolysis)
-Results in renal failure in severe cases.
-Patient complains of exercise induced myalgia then ask about "Cola colored" or "red colored” urine during this episodes. 

That's all for today.
I hope it helped.
In next post I will continue with the relation of age and progression to diagnose myopathy. 


-Upasana Y. :)

Emphysematous Cholecystitis

Hello guys! Here's a brief description about Emphysematous Cholecystitis.

What are the risk factors for Emphysematous Cholecystitis?

1. Diabetes Mellitus (Most Important)
2. Immunosuppresion
3. Vascular compromise (Obstruction & stenosis of Cystic artery).

Emphysematous Cholecystitis is a life-threatening form of Acute cholecystitis & caused due to infection of the gall bladder wall with Gas forming bacteria like: Clostridium welchi.
Gas forms in gall bladder wall with occasional detection of crepitation (that's why called Emphysematous).
Development of gangrene & perforation is common.
It is managed by Emergency cholecystectomy with broad spectrum antibiotics.

Thank you
MD Mobarak Hussain (Maahii)

How to study for USMLE Step 2 CK

If you are short of time, don't read this. Seriously, if you have 2-3 months to prepare - Just do UW, assessments and give the exam. You will do great!

If you have a good 6-12 months, you are just starting your prep and need honest advice, here is mine.

I haven't got my score yet, but the post has been requested before I even gave my exam. So here it is =) I wonder if my credibility changes after my result. Oh well, guess I'll never know.

Medicowesome secret project: Poem on recycling

Medicowesome secret project: Inspiration



Hello Medicowesomites! The secret projects are back!!!! Who is excited??? :D

As you all know, every month, we publish a few stories, pieces of art written by awesomites - which are unrelated to studies.

The theme for this month is - Inspiration.

Medicowesome secret project: Stalking the Future

Medicowesome secret project: The Ordeal

Pills of knowledge in Ophthalmology-Pupil and the third nerve palsy

The parasympathetic fibres passing along with the 3rd cranial nerve which supply the pupil lie towards the periphery of the nerve. Hence, surgical compressive lesions like tumors or aneurysms which compress the 3rd nerve end up involving the pupil as well.

In contrast, medical lesions like diabetis mellitus or hypertension affect the vasa nervosum which supply the nerve starting from its core.These rarely affect the pupil as the outer, peripheral fibres may remain relatively spared.

This however, is not a strict rule.This criterion can just be used for the primary evaluation of the possible lesion.

That's all!


Sunday, July 23, 2017

Triad of Retinitis pigmentosa mnemonic

The mnemonic for remembering the Triad of retinitis pigmentosa (RP) is BAD

1. B- jet Black spots which are perivascular.
2. A- Attenuation of arterioles.
3. D- Disc palor.

Thanks for reading.

Madhuri Reddy

Injury to spinal accessory nerve

Hello friends,

This post is about damage to spinal accessory nerve.

We know that this nerve in the neck first supplies sternocleidomastoid,then lies on levator scapulae to supply trapezius.

On excision biopsy for matted cervical lymph nodes,we may damage that part of nerve which is lying on levator scapulae.So, this may lead to paralysis of trapezius.

To find this:

Ask the patient to shruggle his shoulder,

To do overhead abduction of arm, and

See for winging of scapula at rest.

On paralysis, there will be difficulty in shruggling his shoulders , difficulty in overhead abduction of arm and winging of scapula at rest.

Winging of scapula is also seen in paralysis of serratus anterior but prominent on movement like pushing the wall, whereas in paralysis of trapezius, it's seen at rest.

Thanks for reading!

Madhuri Reddy (Madhu)

Myopathies series -Part 3


Hello! :)

In previous post, I discussed about metabolic myopathies.
Today we see the general classification of myopathies.

Myopathies are classified as

-CONGENITAL
-ACQUIRED

I. CONGENITAL:-

1. Denervation atrophy;-
-spinal muscular atrophy (infantile motor neuron disease)

2. Muscular dystrophies

a) Autosomal recessive Muscular dystrophy 
-Limb-girdle form

b) Autosomal dominant muscular dystrophy
-Facioscapulohumeral
-Occular

c) Sex linked muscular dystrophy
-Duchene 
-Becker
-Emery Dreifuss

3. Myotonic dystrophy

4. Ion channel myopathies

5. Congenital myopathies

6. Myopathies associated with inborn errors of metabolism (This we have already studied in previous posts.)

II.ACQUIRED MYOPATHIES

1. Inflammatory myopathies

-Infectious
-non-Infectious
-systemic inflammatory disease (involves other organs also)

2. Toxic myopathies

-Thyrotoxic myopathy (There is an awesome post By Ojas )
http://www.medicowesome.com/2017/03/pathophysiology-of-myopathy-caused.html

-Ethanol myopathy
-Drug induced myopathy

So this means, we have long way to go: D


 "MOTOR ACTIVITY” is a broad term. It includes 
1) Voluntary movements 
2) Reflex movements
3) Rhythmic motor patterns

The pathway of any motor activity includes:

1. Cortical level
2. Brainstem and associated structures 
-Brainstem centers 
-Basal ganglia
-cerebellum

3. Spinal cord
4. Lower motor neurons
5. Neuromuscular junction 
6. Muscle 

 Myopathy means we are discussing problem in MUSCLES.
So how do we know the correct site of lesion?

To diagnose any myopathy, we need to know its site and cause of lesion. The following helps in the diagnosis.
1. History
2. Examination
3. Investigations 

Take care.
-Upasana Y. :)

Brain Abscess - Important facts

Hello guys! Here are some important facts about Brain Abscess.

Most Common site: Frontal lobe

Sequence of involvement: Frontal lobe > Temporal lobe > Parietal Lobe > Occipital lobe.

Most Common site of Brain Abscess in Tetralogy of Fallot: Parietal Lobe.

Most Common site of Brain Abscess in CSOM: Temporal lobe (Mastoiditis).

Most Common organisms involved are Anaerobic bacteria > Staphylococcus aureus > Streptococcus pyogenes.

Empirical therapy: Vancomycin + Ceftriaxone + Metronidazole for 4 to 8 weeks.

I hope that it's helpful to you.
Thank you!

MD Mobarak Hussain (Maahii)

Granulomas and hematolymphoid malignancies

Granulomas are rare findings in a bone marrow of hematolymphoid malignancies. They are commoner with Hodgkin lymphoma and rarer with acute leukemias. They are most commonly non caesating epitheloid granulomas and may stain negative for tuberculosis and fungi! So, what are they really? They are believed to be a immune response to tumour antigens or to immune complexes when the patient is on treatment...
All granulomas need not be tubercular!

Saturday, July 22, 2017

Branches of subclavian artery mnemonic

Hello friends,

Today let's memorise the branches of subclavian artery.

The mnemonic is  VITamin 'C ' and 'D'

Here VIT corresponds to branches arising from first part. 

'C' from second part. 

'D' from third part  of subclavian artery.

So from first part:

V - Vertebral

 I - Internal thoracic artery

T - Thyrocervical trunk or Thyroscapulocervical trunk( this makes our task easy to memorize branches of this trunk)

Thyroscapulocervical - Gives  rise to 3 arteries:

Thyro -- Inferior thyroid artery

Scapul-- suprascapular artery

Cervical - superficial cervical artery.

From second part:

C - Costocervical trunk which gives rise to superior intercostal artery and deep cervical artery.

From third part:

D - Dorsal scapular artery.

Sometimes, instead of superficial cervical and dorsal scapular arteries arising as 2 separate arteries, there is a single branch which arises from 1 st part of subclavian artery that is Transverse cervical artery.

This artery divides into superficial ascending branch and deep descending branch as shown in the flow chart below.

Thanks for reading and do correct me if there is anything wrong.

Madhuri Reddy (Madhu)

Rash involving hands and feet mnemonic

This is the association I use to remember the organisms causing rash that includes hands and feet - You drive CARS with your hands and feet. 

CA- Coxsackie A virus
R- Rickettsia rickettsii 
S- Syphilis (secondary)
S - Staphylococcus (TSS) 

We often forget Toxic Shock Syndrome in our differential. Keep it in mind! 

That's all! 
-IkaN 

Hypervitaminosis A mnemonic

Hello!

Here's a mnemonic to remember the features of Hypervitaminosis A.

The mnemonic is, "H.A.R.D. Puzzle."
H - Hepatosplenomegaly, Hair sparse, Hyperostosis
A - Anemia, Anorexia
R - Really painful bones
D - Dry skin
Puzzle - Pseudotumor cerebri

Thank you.

MD Mobarak Hussain (Maahii)

Necrotizing Enterocolitis - Important points

Here are some high yield points about Necrotizing Enterocolitis.

1. It is the most common life threatening emergency of gastrointestinal tract in neonates.

2. Triad of - Intestinal ischemia, enteral nutrition and bacterial translocation.

3. Distal part of Ileum and proximal segment of colon are most frequently involved.

4. Coagulation necrosis is the characteristic histological finding in the intestinal specimens in Necrotizing Enterocolitis.

5. Pneumatosis intestinalis (air in the bowel) is diagnostic on X-ray.

6. Portal venous gas shadow is a sign of severe Necrotizing Enterocolitis on X-ray.

7. Most important risk factor is Prematurity.

8. Pneumoperitoneum is a sign of advanced NEC with perforation.

These points should help you in quick revision.

Thank you!

MD Mobarak Hussain (Maahii)

Lung Cancer Subtypes

Subtypes of lung cancer:-
1. Squamous cell cancer-
Most common variant in India.
Smoking is a risk factor.
Central in location.
Local growth is surgically resectable.
Cavity formation is seen.

2. Adenocarcinoma-
Most common variant of lung cancer overall.
Most common lung cancer among non smokers.
Peripheral in location.
Transbronchial spread i.e. it arises at one lobe and spreads to the another lobe.

3. Small cell carcinoma/Oat cell carcinoma-
Most aggressive variant.
Smoking is a risk factor.
Central  in location.
It exhibits micrometastasis.
It has worst prognosis.

4. Large cell carcinoma-
Observed in Non smokers.
Peripheral in location.
This is associated with Estrogen production which manifests as Gynecomastia.

I hope this will help you to distinguish between the various subtypes.

Thank you
-Md Mobarak Hussain (Maahii)

Friday, July 21, 2017

Oxalate stones in Crohn's Disease

A tricky Concept based question often asked in Medicine/Pathology MBBS Professional Exam-
Why Crohn's Disease patient often develop Kidney/Renal STONES, particularly OXALATE stones?

Tachyarrhythmias

Here are some high yielding MCQ points on arrhythmia

Most common arrhythmia mechanism is re-entry.
Most common sustained arrhythmia is atrial fibrillation.
Most common benign rhythm identified is atrial premature contraction.
Most common arrhythmia in COPD patient is multifocal atrial tachycardia.
Post operative atrial fibrillation is managed with landiolol hydrochloride.
Atrial fibrillation getting converted to ventricular fibrillation is seen with accessory pathway conducting antegradely like Bundle of Kent in WPW syndrome.
VT storm or electrical storm is  3 or more separate episodes of VT within 24 hours.
Most commonly identified arrhythmia in cardiac arrest patient is ventricular fibrillation.
Most common cause of Sudden death in HCM is polymorphic VT/Ventricular fibrillation VF.

Thank you

-Md Mobarak Hussain (Maahii)

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