A 12-year-old boy presents with a crusted honey-brown lesion that affects his face

A 12-year-old boy presents with a crusted honey-brown lesion that affects his face. The rash began as red macules 3 days earlier. The best treatment is

A) Intramuscular ceftriaxone
B) Topical hydrocortisone cream
C) Oral ciprofloxacin
D) Topical mupirocin ointment
E) Oral acyclovir

Answer:

Introduction to Herpes zoster

Introduction

Also called shingles, herpes zoster is an acute unilateral and segmental inflammation of the dorsal root ganglia caused by infection with the herpesvirus varicella-zoster, which also causes chickenpox. 

This infection usually occurs in adults. It produces localized vesicular skin lesions confined to a dermatome and severe neuralgic pain in peripheral areas innervated by the nerves arising in the inflamed root ganglia.

The prognosis is good unless the infection spreads to the brain. Eventually, most patients recover completely, except for possible scarring and, in corneal damage, visual impairment. Occasionally, neuralgia may persist for months or years.
Herpes zoster is found primarily in adults, especially those older than age 50. It seldom recurs.

Pathophysiology
Herpes zoster results from reactivation of varicella virus that has lain dormant in the cerebral ganglia (extramedullary ganglia of the cranial nerves) or the ganglia of posterior nerve roots since a previous episode of chickenpox.
Exactly how or why this reactivation occurs isn’t clear. Some believe that the virus multiplies as it’s reactivated and that it’s neutralized by antibodies remaining from the initial infection. However, if effective antibodies aren’t present, the virus continues to multiply in the ganglia, destroy the host neuron, and spread down the sensory nerves to the skin.

Clinical features
Herpes zoster usually runs a typical course with classic signs and symptoms. Serious complications sometimes occur.

Onset of disease
Herpes zoster begins with fever and malaise. Within 2 to 4 days, severe deep pain, pruritus, and paresthesia or hyperesthesia develop, usually on the trunk and occasionally on the arms and legs in a dermatomal distribution. Pain may be continuous or intermittent and usually lasts from 1 to 4 weeks.

Introduction to Mumps

Also known as infectious or epidemic parotitis, mumps is an acute viral disease caused by a paramyxovirus. It’s most prevalent in unvaccinated children between ages 2 and 12, but it can occur in other age-groups. Infants younger than age 1 seldom get this disease because of passive immunity from maternal antibodies. Peak incidence occurs during late winter and early spring.

The prognosis for complete recovery is good, although mumps sometimes causes complications.

Etiology

The mumps paramyxovirus is found in the saliva of an infected person and is transmitted by droplets or by direct contact. The virus is present in the saliva 6 days before to 9 days after onset of parotid gland swelling; the 48-hour period immediately preceding onset of swelling is probably the time of highest communicability.

The incubation period ranges from 14 to 25 days (the average is 18 days). One attack of mumps (even if unilateral) almost always confers lifelong immunity.

Signs and symptoms
Signs and symptoms of mumps vary widely. An estimated 30% of susceptible people have subclinical illness. Mumps usually begins with prodromal signs and symptoms that last for 24 hours; these include myalgia, anorexia, malaise, headache, and low-grade fever, followed by an earache that’s aggravated by chewing, parotid gland tenderness and swelling, a temperature of 101° to 104° F (38.3° to 40° C), and pain when chewing or when drinking sour or acidic liquids. Simultaneously with the swelling of the parotid gland or several days later, one or more of the other salivary glands may become swollen.

Herpes Zoster Opthalmicus

A middle aged lady presented with a vesicular rash on her face that was seen to be involving the ophthalmic division of the trigeminal nerve.

The case was diagnosed as Herpes Zoster Opthalmicus

Case Discussion:
Reactivation of endogenous latent varicella-zoster virus within the trigeminal ganglion with neuronal spread through the ophthalmic branch results in crops of grouped vesicles on the forehead and periocularly.

Clinical features; Patients typically present with periocular rash and an injected eye, along with a watery discharge. The most common corneal lesion is punctate epithelial keratitis, in which
the cornea has a ground-glass appearance because of stromal edema. Pseudodendrites, also very common, form from mucous deposition, are usually peripheral, and stain moderate to poorly with fluorescein. These may be differentiated from the dendrites of herpes simplex in that the pseudodendrites lack the rounded terminal bulbs at the end of the branches, and are broader and more plaquelike. Anterior stromal infiltrates may be seen in the second or third week after the acute
infection. Follicles (hyperplastic lymphoid tissue that appears as gray or white lobular elevations, particularly in the inferior cul-de-sac) and regional adenopathy may or may not be present. Iritis is seen in approximately 40% of patients.

Infections Causes By Herpes Simplex Virus

Herpes Simplex virus infection may be caused by type I or type II virus and the infection may be primary or recurrent.

Primary Infection
The manifestations of primary Infection includes:

1. Systemic infection: e.g fever, sore throat and lymphadenopathy that may pass unnoticed. If the patient is immunocompromised, then the disease may become life threatening with fever, lymphadenopathy, pneumonitis and hepatitis.

2. Gingivostomatitis: Ulcers filled with yellow slough appear in the mouth.

3. Herpetic Whitlow: A breach in the skin that may be due to any minor trauma allows the virus to enter the finger, causing a vesicle to form. Often this condition is seen in children nurses.

4. Traumatic Herpes: Also known as Herpes gladiatorum. In this condition vesicles develop at any site where herpes simplex virus have been inoculated on the skin by brute force.

5. Eczema Herpeticum: HSV infection superimposed on eczematous skin. Usually seen in children.

Central venous Line/ Catheter Related Infections In ICU Setting.

Introduction:
Majority of patients in ICU have central venous lines placed in order to provide fluids and medicines. They may be life saving but at the same time these can result in serious blood stream infections. These catheter related blood infections are reported to occur in about 3 to 8% of inserted catheters and are the number one cause of nosocomial infections in ICU settings.

A few Definitions:
1. A central venous catheter or a central venous line is a catheter whose tip resides in a central vein.

                                                       An Adult Central venous catheter 

2. Catheter related blood stream infections refer to an infection that is attributed to an intravenous catheter by quantitative culture of the catheter tip or by difference in growth between catheter and peripheral venipuncture blood culture specimens.

3. Central line associated blood infections is defined as an infection that appears in the presence of a central venous catheter or within 48 hours of removal of a central venous line and which cannot be attributed to an infection unrelated to the catheter.

Risk factors:
The risk factors for these central venous line related blood infections include :

• Patient’s severity of illness
• Compromised immune system
• Presence of a distant skin infection
• Site of the catheter with greatest chances of infection with groin insertions.
• If aseptic techniques are not proper;y used while insertion of the catheter.

A 19 Year Old Woman With Fever And Sore Throat

A 19-yr-old woman presents with a severe sore throat, fever and malaise. She has marked cervical lymphadenopathy, gross splenomegaly and scattered petechiae on the soft palate, with enlarged tonsils covered by a confluent white exudate.

Her White cell count is mildly elevated, her serum ALT and AST concentrations are twice normal and her ALP is slightly elevated.
Which one of the following investigations is most likely to help guide your management?
A. FNA of a LN
B. HBsAg
C. CMV IgM
D. Heterophilic antibodies
E. HIV test

Answer:

A 19-yr-old woman Presents with Fever, Rash and Cough.....

A 19-yr-old woman presents with fever, rash and cough, and is pyrexial, tachycardic and tachypnoeic. She has a florid erythematous rash on her face, trunk and arms, with scattered whitish papular lesions on the buccal mucosa.

What is the most likely Dx?
A. Meningococcaemia
B. Rubella
C. Parvovirus B19
D. Secondary syphilis
E. Measles

Answer: E. Measles

Discussion: Adult measles is unusual except in non-immunised persons. The description of this Pt’s rash is classical: the rash is maculopapular, starts on the face and migrates caudally; Koplik’s spots are present in the mouth.

In contrast, meningococcaemia is a petechial/purpuric macular rash with no buccal lesions, and there is no typical migratory pattern.

Cellulitis - A Brief Discussion

Cellulitis is a common infection of the skin or subcutaneous tissues with characteristic findings of:

• erythema with poorly defined borders, 
• edema, warmth, pain, and limitation of movement.
• Fever and constitutional symptoms may be present and are commonly associated withm bacteremia. 

     Cellulitis of the right lower extremity characterized by sharply demarcated erythema an edema.

Predisposing factors include:

• trauma, 
• lymphatic or venous stasis, 
• immunodeficiency (including diabetes mellitus), and 
• foreign bodies.

Common etiologic organisms include:

• group A β-hemolytic Streptococcus 
• Staphylococcus aureus in nonintertriginous skin, and  gram-negative organisms or mixed flora in intertriginous skin and ulcerations. 
• In immunocompromised hosts, Escherichia coli, Klebsiella species, Enterobacter species, and Pseudomonas aeruginosa are common. 
• In recent years, there has been a dramatic increase in the incidence of community- acquire methicillin-resistant S aureus (CA-MRSA), particularly in cellulitis associate with a cutaneous abscess.

A 19 Year Old Male With Cough, headache and Malaise...

A 19-yr -old army cadet is admitted to hospital with cough, headaches and malaise. He has a temperature of 38°C. His blood count and renal and liver function are normal. Cold agglutinins
are positive. A CXR shows bibasal shadowing.

What is the most likely Dx?

A. Legionella pneumonia
B. Viral pneumonia
C. Q fever
D. Klebsiella pneumonia
E. Mycoplasma pneumonia

Answer:

SARS- Severe Acute Respiratory Syndrome -- Charts

Guinea worm disease (Dracunculiasis) - A Rare Case

A 36 years old male came to radiology department for X-ray chest with history of cough since one week. His X ray shows a rare finding in which the lung fields are clear, however, there are a string
like linear high density calcified guinea worms in the right axillary soft tissues. The X ray is shown below:

X-ray right knees (shown below) was done which shows calcified guinea worms in the soft tissues of the distal posterior aspect of thigh.

Case Discussion: Transmission of dracunculiasis has been eradicated all over the world except only a few African countries. Man acquires infection by drinking water containing infected cyclops. In the stomach these cyclops are digested by gastric juice and the parasites are released.

Measles - A Quick Review -- Charts

Chicken Pox -- Charts

Athlete's Foot Or Tinea Pedis

Athlete's foot is also known as tinea pedis. It is usually caused by fungi in the genus Trichophyton and affects the skin on the feet.
Athlete's foot is one of the most common fungal skin infections. 

Athlete's foot fungus may infect any part of the foot, but most often grows between the toes.

Causes And Risk Factors: Athlete's foot spreads easily. You can get it by touching the toes or feet of a person who has it. But most often, people get it by walking barefoot on contaminated surfaces near swimming pools or in locker rooms. The fungi then grow in the shoes, especially if the shoes are so tight that air cannot move around the feet.

Risk factors for getting infected with Athlete's foot are: 

• Male gender
• People who frequently wear damp socks or tight fitting shoes
• Sharing mats, rugs, bed linens, clothes or shoes with someone who has a fungal infection
• Walking barefoot in public areas where the infection can spread, such as locker rooms, swimming pools, communal baths and showers.

Clinical Features: Athlete's foot usually causes a scaly red rash.

A Case Of Syphilis

A 39-year-old woman presents with a non healing ulcer over her upper lip (picture shown below) for 1 week and a new-onset rash on her trunk .
The ulcer on her upper lip was misdiagnosed as herpes simplex by the previous physician. Sexual history revealed that the patient had oral sex with a boyfriend who had a lesion on his penis and she suspected that he had been having sex with other women.

The examining physician recognized the nonpainful ulcer and rash as a combination of primary and secondary (P&S) syphilis. An RPR (rapid plasma reagin) was drawn and the patient was treated immediately with IM benzathine penicillin. The RPR came back as 1:128 and the ulcer was healed within 1 week.

Case Discussion:

Syphillis: 
Syphilis, caused by Treponema pallidum, is a systemic disease characterized by multiple overlapping stages:

• primary syphilis (ulcer), 
• secondary syphilis (skin rash, mucocutaneous lesions or lymphadenopathy),
• tertiary syphilis (cardiac or gummatous lesions), and 
• early or late latent syphilis (positive serology without clinical manifestations).
• Neurosyphilis can occur at any stage. 

A 21 year Old man Presents With A Rash On His Feet

An 21-year-old surfer presents to your office with a rash that he noted on his foot. The vesicular rash has been present over the last week and has been enlarging.
The rash is shown in picture below:

The most likely diagnosis is
A) Sea lice
B) Cutaneous larva migrans
C) Swimming pool granuloma
D) Jellyfish sting
E) Bathing suit dermatitis

Answer And Discussion:

A 30 year old man Presents with Acute Painful Swelling of the Right Parotid

A 30 year old man presents with acute painful swelling of the right parotid for 1 day.
Answer the following questions:
1. What 3 questions you would ask in history?
2. What examination would you conduct?
3. What will be your management plan?

( Question from MCPS paper October 19th 2016).

                                                   Acute swelling of the parotid . 


Solution:
1. What 3 questions you would ask in history?

Answer:

Giardiasis

Which of the following statements about giardiasis is true?
A) Transmission occurs through fecal–oral contamination.
B) Chlorination of drinking water kills the cyst.
C) Diagnosis can be achieved by peripheral blood smears.
D) The cyst form is responsible for symptoms.
E) Asymptomatic carriers do not require treatment.

Answer and Discussion
The answer is A.

Giardia lamblia is the causative agent in parasitic giardiasis. Most cases are asymptomatic. However, these patients pass infective cysts and must be treated.

Rocky Mountain spotted fever (RMSF).

A 35-year-old who has recently returned from an early summer fishing vacation in rural
North Carolina presents with a febrile illness. He reports a 5-day history of fever, malaise, headache, and vomiting. Today, he has developed a nonpruritic rash that began on his extremities and has spread to his body.
On exam he has a fever of 38.3◦C with a pulse of 120 and otherwise normal vitals. The rash is maculopapular and generalized, involving his palms and soles. Oral mucosa is dry but intact, and the exam is otherwise nonspecific.
Basic investigations were done and CBC shows mild thrombocytopenia but is normal otherwise. BUN and creatinine are at the upper limits of normal, and the electrolytes are normal.

The rash on his hand and feet is shown below:

What is the most likely Diagnosis?

Rocky Mountain spotted fever (RMSF).

Case Discussion:

Rocky Mountain spotted fever RMSF is a tick-borne (dog or wood tick) disease caused by Rickettsia rickettsii. Despite its name, RMSF is endemic in the southeastern United States, the Atlantic states, and the northern Rocky Mountains.

Clinical features: It presents with a prodrome of fever and headache several days before the onset of the characteristic rash—a maculopapular eruption that begins at the wrists and ankles and spreads centrally. Eventually, the rash becomes petechial.