Flashcards in Tucker- skin manifestations of disease Deck (28):
Causes of purpura, e.g.
HSP (Henoch Schonlein)
Purpura Fulminans (meningococcal)
differential of a child with petechiae
Infectious, hematologic, immunologic, and traumatic
Infectious causes: Rocky Mountain Spotted Fever, sepsis with meningococcemia, pneumococcemia in particular, atypical measles.
When they occur as an enanthem, you can see them in Strep (palatal petechiae) or Mono. Coagulation disorders, ITP, TTP, Leukemia. Vasculitis, anaphylactoid purpura, or HSP.
Rocky Mountain Spotted Fever
Most common fatal tick-borne disease in the United States
- Caused by Rickettsia rickettsii
- Multiple tick vectors, incl. American dog tick, the common brown dog tick, and the Rocky Mountain wood tick
A tick must feed for 6 hours before infection transmission occurs, and Rickettsia replicate for an average of 1 week before clinical symptoms begin.
The incidence is highest in individuals aged 5-9 and 60-69 years
Majority of cases occur between April and September in the Southeast and Midwest United States
Most common symptoms are:
- high fever (> 102° F)
petechial rash typically begins on the wrists and ankles but may be found anywhere, including the oral mucosa, as in this child
spotless RMSF occurs in 10%-15% of cases
A high index of suspicion must be maintained, as the mortality rate is 20%-30% for untreated patients and 1%-5% for treated ones
Empiric antibiotic therapy is usually initiated based on the history and physical examination, without waiting for confirmatory serologic testing
- delay between presentation and diagnosis of RMSF
3/4 may require hospitalization
Outpatients must be closely monitored, as rapid deterioration is not uncommon and requires subsequent admission.
- gram-negative diplococcus Neisseria meningitidis
- transmission is person-to-person via respiratory droplets, often from an asymptomatic carrier
- Up to 30% of teenagers and 10% of adults carry meningococci in the upper respiratory tract.
Clinical presentation is variable
- 50% of patients developing meningitis only
- 10% developing septicemia only
- 40% developing both
usually febrile, ill-appearing, lethargy, vomiting, and nuchal rigidity
Septicemia leads to capillary leak, coagulopathy, profound acidosis, and myocardial failure
Septic emboli cause arterial occlusion in the distal extremities
- must be closely monitored for hypotension, shock, pericarditis, organ failure, and coagulopathy, usually in an intensive care unit setting
- Patients with coagulopathy and gangrene may be candidates for anticoagulation therapy.
- In patients with both septicemia and meningitis, a depressed level of consciousness may be from elevated intracranial pressure or hypotension
mortality rate, even with prompt treatment, is 5%-10%
If suspected, antibiotic treatment should be initiated without waiting for confirmatory culture testing
** Important note: Pneumococcus can have a very similar presentation to Meningococcemia
One of the most contagious infectious diseases, with a secondary infection rate of 90% in susceptible individual
- vaccine introduced in 1963 --> a reduction in annual incidence in the United States of greater than 99%
- it remains one of the leading causes of death in young children worldwide, with an estimated 197,000 deaths yearly
- After exposure, the incubation period lasts for 7-14 days
- Then prodrome of high fevers, often > 104° F, with the classic triad of cough, coryza, and conjunctivitis
- A couple of days later, Koplik spots develop on the buccal mucosa, appearing as white spots on an erythematous base.
- W/i a couple of days after the Koplik spots appear, an exanthem develops which consists of blanching, erythematous macules and papules, as shown
--- begins on the face at the hairline and coalesces into patches and plaques that spread cephalocaudally to the trunk and extremities
--- this lasts for a week before fading to hyperpigmented patches which desquamate
- Vitamin A deficiency has been associated with a worse prognosis, including blindness, so all children diagnosed with measles receive supplementation
- Care is otherwise supportive with adequate hydration.
- Subacute sclerosing panencephalitis is a late, long-term complication caused by persistent infection
ALL the most common malignancy of childhood
- Often presents with nonspecific symptoms of anorexia, irritability and lethargy
- may follow a mild respiratory infection
- Subsequently one may see progressive fatigue, weight loss, pallor, bone pain, fever and petechiae
Peak incidence at age 4, more common in whites than blacks, more common in boys than girls.
TTP/ Hemolytic-Uremic Syndrome
Classic presentation is 5-10 days after developing gastroenteritis
Frequently associated with bloody diarrhea (E. coli O-157)
patient develop progressive renal failure, anemia, thrombocytopenia
(HUS may be the childhood version of TTP)
Most common cause of thrombocytopenic petechiae in childhood
- associated with bleeding and bruising
Most commonly preceeded by an acute viral illness 2-4 before presentation
** Platelet counts often are below 20,000 (antibodies consume every platelet that comes out, as opposed to leukemias)
Most serious complication is intracranial bleed but this is very rare due to etiology of disease
- Autoimmune destruction of platelets resulting in large, new, very effective platelets, although low in numbers, most severe bleeds do not occur
Need to differentiate from infiltrative disease such as Leukemia, neuroblastoma etc.
(many treated with IV IG now)
vasculitis that can affect the skin, joints, gastrointestinal tract, and kidneys
- In a well-appearing child, HSP can be managed on an outpatient basis.
-- helpful to check blood pressure, urine, and electrolytes to look for a glomerulonephritis
-- Urinalysis and blood pressure may be followed for several months to monitor kidney function
- fecal occult blood test can help rule out significant gut involvement, especially in children with pain
- Intussusception is the most serious complication of HSP; if it is suspected, the child should be admitted and monitored.
- Platelet count is generally normal in HSP, helping to differentiate it from idiopathic thrombocytopenic purpura (ITP), which has low platelets
-- ITP presents with petechiae, bruising (as shown), or bleeding, often in areas of trauma
-- If counts are sufficiently low, there is a risk for intracranial bleed
Treatment: A consult with hematology can help determine appropriate management in case of uncertainty.
classic picture: rash, blood in the urine, abdominal pain
some get chronic renal disease but this is rare
Chicken pox progression
starts as a red macule--> papule--> vesicle--> crust
the vesicle: "dew-drop on a rose petal"
starts on torso and spreads centrifugally-- outwards.
lesions come in crops
opthalmic involvement of herpes
take antiviral eye drops to avoid the dreaded herpes keratitis (--> damaged vision/ blindness)
hypothermic baby with vesicles on the scalp. WHat did he have?
neonatal herpes. --> skin manifestations of herpes, encephalitis, etc.
what causes bullae? (in particular, an infectious agent)
staph aureus. Bullous impetigo
staph can also cause scalded skin syndrome
is an enanthum
scarlet fever-- maculopapular rash, increased in popliteal space, groin, cubital region
--> rheumatic fever if you don't take ABX
causes of hives
pressure on the skin of people with dermatographism
terrible allergic reaction; bump --> target leasions--> mucous membrane involvement --> peel (sloughing)
classically related to sulfa drugs
flat, maculopapular pink rash, lacy reticulated pattern
pay attention to transplacental transmission; --> hydrops fatalis
watch out esp. in sickle cell; bone marrow crisis is particularly bad with them
high spiking fever
it breaks; a couple days later get exanthum
Ringworm, Nummular eczema
These 2 rashes are very difficult to tell apart and without a fungal culture almost impossible.
However, we often will treat one or the other and if it doesn't work, treat the other.
- tinea can also be very impressive in it's appearance in tinea capitis
- especially in black children you may see a Kerion, these require treatment with Griseofulvin for about 6 weeks, they can be confused with abscesses as they can ooze pus like material
christmas tree like rash on the back
lasts 4-6 weeks
nobody knows what causes it
The classic lesions are:
- ash leaf macule (often present at birth, most easily seen with a wood's lamp)
shagreen patch (raised orange peel appearance)
adenoma sebaceum (skin colored or pink lesion often present on face in late childhood to early adolescence)
- which is a misnomer as they are actually fibroadenomas and have nothing to do with the sebaceous glands
chromosome 9 or 16
port wine stain
large macule , vascular in nature
consider Sturge- Weber (classic for this disorder)
can be devastating; result of a capillary hemangioma which involves the skin of the face, mucous membranes, meninges and choroid plexus
You may see seizures, hemiparesis, hemianopsia and intellectual impairment
usually lesions are unilateral
due to altered immune regulation
- classic systemic lupus is multisystem disorder
- essentially can effect every organ system
- discoid lupus only has dermatologic manifestations
cafe au lait spot and axillary freckling
NFM type 1
> 6 cafe au lait spots over 1.5 cm plus axillary freckling
tend to have short stature
has multiple skin manifestations
cafe au lait spots commonly found in normal individuals, but more than 6 > 1.5 cm is pathognomonic for neurofibromatosis
often axillary freckling and increase in hyperpigmentation in the skin
cutaneous and subcutaneous neurofibromas appear in late childhood or adolescence
One may also see large unilateral cafe au lait spots in Mccune Albright syndrome
- this disorder includes polyostotic bone dysplasia, precocious puberty and multiple endocrine dysfunctions