Pediatric dermatology

Question 1

Lines of blaschko

Answer 1

Represent pathways of epidermal cell migration and proliferation during the development phase of the fetus

• look v and s shaped and never cross anterior truncal midline
• are always present but only apperant with pathology is present

Pathology possible:

• MLS syndrome, KID syndrome, MIDAS syndrome
• sebaceous naevus
• lichen stratus or planus
• vitiligo

Question 2

Neonate skin

Answer 2

Is less hairy, less sweat and sebaceous gland secretions

Possess fewer melanosomes

• *not well equipped to handle thermal stress and sunlight well and have increased transepidermal water loss and penetration of toxic substances and medications**
• because of this it is usually discouraged to put anything on a child’s skin (except petroleum jelly)
• also make sure they are well clothed and protected

Are most likely to get blisters/erosions in response to damage

Question 3

When does keratinization of neonates occurs

Answer 3

24 weeks old
- most of the barrier properties of the skin reside primarily in the stratum corneum

Between 24-36 weeks, baby is very prone to water loss and toxic absorption through skin

Question 4

When does the skin barrier become matured in neonates

Answer 4

36 weeks gestational age

Can be delayed by premature birth, epidermal injury, inflammation or Hyperemia
- also sepsis and ischemia can do the same

** even at this point, they have a increased surface-to-volume ratio compared to adults which leads to high transcutaneous absorption**

Question 5

Some common percutaneous absorption and effects

Answer 5

Aniline dyes = methemoglobinemia

Topical corticosteroids = adrenal suppression and systemic effects

Hexachlorphene = vacuolar encephalopathy

Pentachlorophenol poisoning via direct contact

Povidone-iodine = elevated iodine and thyroid dysfunctions

Any alcohol = liver damage

Question 6

What is the vermix of babies?

Answer 6

Greasy white material that covers the neonate skin
- unknown function but is more basic (7.4) than the neonate skin (5.5)

• *washing this off neonates leads to decrease in normal barrier function of the stratum corneum**
• because of this, only wash with tap water or saline compresses and avoid harsh soaps (still wash to remove cutaneous bacteria)

Question 7

Cutis marmorata

Answer 7

Reticulate cyanosis or marbling of the skin of the trunk and extremities symmetrically.
- can also be paired with acrocyanosis which is where the hands and feet are symmetrically blue in color without edema or cutaneous changes

both cutis marmorata and acrocyanosis resolve usually with warming of the skin and is benign

Question 8

Erythema toxicum neonatorum (ETN)

Answer 8

• *Most common pustular rash and occurs in up to 70% of full term infants
• occurs in 2nd-3rd day of life but can be as long as 2-3 weeks
• is rather abrupt with onset

Shows 2-3 mm diameter erythematous blotchy macules and papules
- can evolve overtime to a “flea-bitten” appearance

Wright stain shows sheets of eosinophils inside the pustules
- also 20% of patients show eosinophilla

Is a benign rash and is harmless

Question 9

Transient pustular Melanosis (TNPM)

Answer 9

Occurs in 4% of newborns and especially in black male infants
- usually prenatal acute onset with 2-5mm diameter pustules that are NON-ERYTHEMATOUS

Over several days the lesions with develop a central crust which leaves to a hyper pigmented macula with collarette of fine scale
- can also show brown macules with a rim of scales

In white babies does not usually show hyperpigmentation with central crust

Wright stain also shows numerous neutrophils**

Question 10

Milia

Answer 10

Pearly yellow tiny papules (1-3mm diameter)
- show on face, chin and forehead usually and present in roughly 50% of newborns

Histology shows miniature epidermal inclusion cysts**

Is normal**

Question 11

Neonatal acne

“Neonatal cephalad pustulosis”

Answer 11

Mild acne that develops in 20% of average onset of 3 weeks

Lesions present at birth or appear in early infancy

• inflammatory (ERYTHEMA) red papules and pustules predominant
• **maybe associated with malassezia yeast species

**doesnt show comedones (open or closed)

Treatment = normally goes away within 1-3 months by itself

• could consider ketoconazole cream but need to consult dermatologist first and usually not necessary
• *there is no correlation with neonatal acne and adolescent acne

Question 12

Periauricular sinuses/pits/tags/cysts

Answer 12

Occur when brachial arches or clefts fail to fuse or close normally

Lesions can be unilateral or bilateral and can be associated with syndromes
- develop along a line from pure auricular area to the corner of the mouth

**these are usually excised at birth

Question 13

Supernumerary digits

Answer 13

Usually appear at the base of the ulnar side of the 5th finger
- mostly associated with familial disorders

Can be locally surgically excised

Question 14

Seborrheic dermatitis in children

Answer 14

Salmon-colored greasy patches along the scalp, axilla, diaper area

• “looks like they have never washed hair”
• sometimes called “cradle cap” if on scalp

Can fissure and weep occasionally

Oval red patches may spread to the proximal extremities and post auricular areas

can also show marked post inflammatory hypopigmentation

• *believed to be partially caused by pityrosporum yeast**
• causes sebaceous glands to be overactive
• known to be present with cradle cap

Treatment = 2-3 months goes always by itself but can persist for 8 months

• can use baby oil or olive oil if only on the scalp
• can use mild keratolytics (zinc pyrithione and salicylic acid)

Question 15

HSV in children

Answer 15

1: 3500 deliveries
- caused by pregnant patients where the lesions in the cervix or vaginal area during the delivery get on the baby (85%)
- *because of this they are often C-section babies
- **mothers are often asymptomatic at delivaery also

Incubation period = 2-21 days and peaks at 6 days
- often appear normal at first in the nursery but then will develop lesions at home after discharge (caused by HSV-2 (85%)

Symptoms vary, but at worst can widely disseminate infection into neuro vascular tissue and kills them
- need to take seriously because of this

Question 16

HSV lesion description

Answer 16

1-2 mm diameter very erythemious clustered papules and vesicles

• often become pustular, denuded and crusted
• can also be hemorrhagic over 2-3 days
• • first lesions are commonly developed on the face and scalp, feet or buttocks (if in the breech presentation)

Question 17

HSV culture results

Answer 17

Show multinucleated giant cells on gimesa stain

Viral cultures are seen in blister fluid

Diagnosis = DFA antibodies on PCR studies

Treatment = parenteral acyclovir

Question 18

Vascular abnormalities in children based on flow characteristics

Answer 18

Infantile hemangioma = fast flow

Capillary malformations = slow flow

Venous malformation = slow flow

Lymphatic malformation = slow flow

Arteriovenous malformation = fast flow

Question 19

Capillary malformations

Answer 19

Salmon patches that are incidental capillary malformations
- occurs in 60-70% of newborns

Usually located on nape of neck, glabella, forehead, upper eyelids and sacrum
- often darken with crying or holding breath

Usually fade without treatment in first year if life
- can rarely persist indefinitely especially on sacrum

Treatment = nothing

Question 20

Port wine stains (PWS)

Answer 20

Capillary malformation that persist and remain unchanged during childhood. Angiomatous papules and nodules underlying soft tissue hypertrophy is seen

• often darken and thicken in adolescence
• these DONT go away
• these are unilateral only

Can use laser treatments to try to get it off

Question 21

Sturge Weber syndrome (SWS)

Answer 21

Segmental vascular neurocutanous disorder
- always presents with a port wine stain at birth and often has leptomeniges malformation

Symptoms

• seizures
• hemiparesis
• TIAs
• headaches
• developmental delay

Question 22

Klippel-trenaunay syndrome

Answer 22

Complex mixed vascular malformation with hypertrophy of bone and soft tissue

• enlargement of tissues is often gradual rather than abrupt
• usually unilateral lower extremities

Anomaly is present at birth and usually involves a lower limb trunk and face

Also shows thick-walled venous varicosities on the ipsilateral side of the vascular malformation once the child begins to ambulate
- tortious veins

Question 23

Infantile hemangiomas (IHs)

Answer 23

Proliferative benign vascular tumors of the vascular endothelium

• are usually bright red in color
• present at 1st-2nd week of life up to a month
• *most common tumor of infancy = 5%**
• risk factors = low birthweight, premature birth, female, white race

Must be classified as superifical, deep or mixed
- most are mixed

Are rapid growing followed by a stationary period and ending with a spontaneous involuntary
- regression often shows pale gray areas centrally (good)

Topical propranolol treats these well or surgical resection can also be used

Question 24

Varicella

Answer 24

Mild, self-limiting infection in most children
- complications can kill however! (Disseminated infections) very common in immunocompromised patients

Must give early administration of the varicella-zoster immune globulin to immunocompromised children
- only give antiviral therapy to immunosupression that currently has varicella

Incubation period: 7-21 days

• fever, sore throat, decreased appetite and malaise
• scattered pruritic red papules that transformed into vesicles on bright red base (“dew drops on a rose petal”)
• late stage = central umbilication of blisters which eventually turn into crusting vesicles that follow off.

Question 25

When are any childhood infections most contagious?

Answer 25

During the prodromal phase of the infection (i.e fever) | - the rash does NOT always coincide with this so the rash cannot be used as a mark of infectivity

Question 26

Hand foot and mouth disease

Answer 26

Coxsackie virus A16 - highly infectious and most common in late fall early summer * *Incubation = 4-6 days - 1-2 day prodromal (fever, dirrhea, sore throat) which is then followed by 3-6mm diameter elongated gray, thin-walled vesicles on red non inflamed base Most commonly seen on palms and soles of feet - lesions rapidly ulcerate if on base tongue and buccal mucosa

Question 27

A6 coxsackie virus hand foot and mouth disease

Answer 27

New clinical variant where the lesions are widespread and looks kinda like herpes - still shows the typical lancet-shaped enteroviral vesicles on the hands and feet however Also presents with worsened prodromal symptoms Treatment = Tylenol/ibuprofen (Will still go away by itself)

Question 28

Impetigo

Answer 28

Shows expanding honey-colored crusty lesions that may or may present with bullae - super super contagious Casued by group A B-hemolytic strep primarily but can also see strep Complications = cellulitis with MRSA - **at this point have to use TMP-SMX or clindamycin** **#1 treatment for simple = cephalexin** **widespread = cefalexin, amoxicillin-clavulanate or erythromycin**

Question 29

Erythema multiforme

Answer 29

Rash is symmetric and can be anywhere - usually on dorsum of hands/feet and extensor surfaces Lesions look like dusty red macules or papules which have a “target appearance” (red around the borders and pale inside) Spreads peripherally and leaves behind a depressed damaged epidermis Multitude of causes**

Question 30

Molluscum contagiosum

Answer 30

Large DNA poxvirus infection that is characterized by sharply circumscribed single or multiple superfical pearly dome shaped papules - start grouped and increase in size to 3-5mm single papules Usually on trunk, axilla, face and diaper area Treatment = if not serious just leave them alone, if serious, excise them - immune system will kill it overtime (6months -2 years) - *can also use cantharidin to blister and then plastic tape to remove (painful though and likely to scar)

Question 31

Keloids

Answer 31

Benign dermal tumors that results from proliferation of fibroblasts in the dermis (caused by some sort of trauma) - results in laying down collagen by fibroblasts which results in the formation of a scar (sometimes can be hypertrophic and continue to thicken and raise)

Question 32

Mongolian spots

Answer 32

Poorly circumscribed gray-blue congenital macules/patches - lesions range from 2mm- 20cm in diameter almost all appear in the lumbroscaral region - biopsy = high density of melanocytes DONOT require therapy, will resolve or be camouflaged by normal skin within 3-5 yrs of age

Question 33

Vitiligo

Answer 33

Acquired disorder of pigmentation which shows a complete loss of pigment in involved areas - lesions are macular in appearance - can progress overtime but usually start small Biopsy shows NO melanocytes in the area - likely autoimmune Treatment = cosmetic approach via temporary camouflage. - also can try high potency corticosteroids or tacrolimus - ALWAYS wear sunscreen and can use light therapy to help

Question 34

Morbilliform drug eruptions

Answer 34

Measles-like macuopapular exanthematous rash that is caused by certain drugs 5-10 days after beginning of drug therapy Starts in trunk and moves out * *almost any drug causes this so just have to watch out - most common = anticonvulsants and antihypertensives Treatment = discontinue drug and pretty much resolves within 1 week **very occasionally can develop into SJS/TEN so MUST take off drug and report which one does this to the person**

Question 35

Rubeola (measles)

Answer 35

Morfilliform rash that occurs in late winter and is NOT tied to drugs - stupid contagious (the most contagious thing) Only occurs in non immunized populations (almost completely eradicated) Symptoms - 10 days of fever, malaise, dry cough, coryza, and severe photophobia - **subsclerosis panencphaltiis can develop 20 years after infection (and just kill you), hence why this disease is taken very seriously even though it doesnt have any chance of immediate death unless your severely immunocompromised. - several days into course, diagnostic “koplik spots” will appear before th erythemous rash appears

Question 36

Koplik spots

Answer 36

Are diagnostic of measles** 1-3mm diameter papules with bluish-white coloration surrounded by a red “ halo” - will increase in number overtime but go away in 1-2 days before the rash begins

Question 37

Measles rash

Answer 37

Usually appears on the 4th day of illness Rash = acute eruption of red macules and papules that travel in a cephalocaudal path over 3 days. Goes away after 10 total days - this rash will blanch with pressure - start to show a rusty hue from hemosiderin deposition and capillary leaks overtime as th papules die off

Question 38

Fifth disease “Erythema infectiosum” or “slapped cheek syndrome”

Answer 38

Caused by parvovirus B19 - is asymptomatic initially except for the rash - rash gets worse with sunlight and fevers and the rash often will spread during the worse conditions instead of just being on face Rash usually fades after 2-3 weeks and doesn’t require treatment * *will experience a transient reticulocytopenia for 7-10 days, but this goes away. Also there is a implication of increased risk of hydrops fetalis in pregnant women** - should make sure pregnant women are immune if around it - also stupid rare but hemoglobinopathies can present with aplastic anemia if the patient gets parvo

Question 39

Roseola “Exanthema subitum” or “surprise rash”

Answer 39

Most common occurs with 6 months - 3 years old - causative agent = HHV6 Prodromal phase for 3-5 days - high fevers, febrile seizures (rare) and malaise - **often will present as a patient with a high fever and you think its strep or ear infections, but there are no signs and so you have to get blood work since the rash doesn’t present** Followed by widely disseminated pink/papillary rash

Question 40

Scarlet fever

Answer 40

Group A B-hemolytic strep is Cause - often preceded by strep pharyngitis or strep throat Shows fine, red, papular, sandpaper-like rash that begins on the fact and neck and moves to the trunk in 1-2 days - also shows pastia lines (flexure lines) with linear petechiae can also show Skin is warm and flushed as well with some mild pruritis ``` Symptoms: N/V - fever headache e - sore throat - pharynx that is swollen red with petechiae - cervical lymphadenopathy - right red strawberry tongue - (+/-) Purulent tonsillitis ``` Complications: - desqumaotion of skin - PSGN Treatment = amoxicillin or penicillin or macrolides (must begin any of these within 10 days) - * does not decrease risk of PSGN