Facts read from pncb.org and 1 more · last checked Nov 7, 2026
Skin is second only to development on PNCB's category list. Most questions show a description rather than a picture, so the distinguishing words (where, what shape, what came first) carry the answer.
Practice questions
60 questions written to the CPNP-PC outline; each choice is explained once you pick.
Newborn and infant: birthmarks, vascular lesions, diaper and seborrheic dermatitis.
Eczema: atopic dermatitis and its infections.
Infections: bacterial, viral exanthems, fungal, and their look-alikes.
Infestations: lice and scabies, treatment and return to school.
Adolescents: acne by severity, drug reactions, rashes with systemic signs.
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15 pediatric skin questions
0 / 15 answered15 questions
Tap an option: why each one is right or wrong appears under it.
Pediatric dermatology
A 5-year-old has generalized hives 1 hour after the second dose of amoxicillin. There is no wheeze, stridor, vomiting, or lip swelling, and vital signs are normal. Which is the MOST appropriate management?
A steroid burst adds little to an antihistamine for acute hives and does not prevent a later reaction.
Hives within an hour of a dose, with no airway, breathing, gut, or circulatory signs, are an immediate skin-only reaction: the drug is stopped, a non-sedating antihistamine eases the itch, and allergy evaluation later clarifies the penicillin label.
Epinephrine is for anaphylaxis, which needs a second organ system or hypotension; giving it for isolated hives in a stable child overtreats.
Continuing a drug that triggered hives within an hour risks a more severe reaction; masking itch with diphenhydramine is not a safe way to finish the course.
A 10-year-old has sore throat, fever, and a fine, sandpaper-like rash on the trunk that is accentuated in the skin folds, with circumoral pallor and a strawberry tongue. The MOST LIKELY cause is:
Enteroviruses cause herpangina or hand-foot-and-mouth vesicles, not a sandpaper rash with circumoral pallor.
Staphylococcal toxins can cause a scarlatiniform rash, but it comes with tender skin and peeling and without the strep throat.
EBV causes exudative pharyngitis with posterior nodes and an enlarged spleen; its rash usually appears after amoxicillin is given.
Pharyngitis with a fine sandpaper rash that is heavier in the skin folds, circumoral pallor, and a strawberry tongue is scarlet fever, caused by toxin-producing group A Streptococcus.
A 14-year-old has moderate acne with inflammatory papules, pustules, and comedones on the face and no nodules. Which initial regimen is MOST appropriate?
A topical antibiotic used alone breeds resistant bacteria and does nothing for comedones; it is paired with benzoyl peroxide if used at all.
Isotretinoin is reserved for severe nodular or scarring acne or failure of combined therapy, not as a first step for moderate acne.
Oral antibiotics are an add-on for moderate to severe inflammatory acne, always with a topical retinoid and benzoyl peroxide and for a limited course, never alone.
For moderate mixed acne, a topical retinoid with benzoyl peroxide treats comedones and inflamed lesions together, and the benzoyl peroxide keeps bacterial resistance down.
A 6-year-old has 8 café-au-lait macules and axillary freckling. The father and paternal grandmother have cutaneous neurofibromas. The parents ask about the risk to a future child. The risk is:
A 25% risk is the autosomal recessive figure, when both parents are carriers; it does not apply to a dominant disorder.
Risk confined to sons describes X-linked recessive inheritance, which NF1 does not follow.
Background risk would apply only if the child's NF1 were a new variant in unaffected parents; here the father and grandmother are affected.
NF1 is autosomal dominant with full penetrance, so an affected parent passes it to each child with a 50% chance regardless of sex.
A 3-year-old with atopic dermatitis develops fever and painful clusters of punched-out erosions with hemorrhagic crusts on the face over 2 days. Which treatment is MOST appropriate?
Cephalexin covers bacterial superinfection of eczema, but monomorphic punched-out erosions with fever mark a viral process that an antibiotic will not stop.
Stepping up the steroid treats this as an eczema flare and can let the herpes infection spread.
A topical antibacterial treats a few infected patches; it neither reaches nor treats disseminated herpes.
Fever with clustered, uniform punched-out erosions on eczematous skin is eczema herpeticum, a herpes simplex infection that needs prompt antiviral therapy and same-day review, with an eye exam if lesions are near the eye.
A 10-year-old with severe atopic dermatitis has disturbed sleep despite adherent use of emollients, medium-potency topical corticosteroid for flares, proactive twice-weekly therapy, and topical tacrolimus. Which is the MOST appropriate next step?
Food IgE panels are often positive without true allergy, and diets built on them restrict nutrition without improving the eczema.
Oral steroids clear skin briefly but cause a rebound flare when stopped, so they are not used to control chronic atopic dermatitis.
Severe atopic dermatitis that still disrupts sleep despite well-used topical steroids, proactive therapy, and a calcineurin inhibitor needs dermatology referral for systemic treatment such as a biologic.
Daily high-potency steroid over the whole body risks skin atrophy and adrenal suppression in a child.
A 12-month-old had 3 days of fever to 40 °C but otherwise appeared well. The day after the fever resolved, a blanching pink maculopapular rash appeared on the trunk and neck. The child is playful and eating normally. The MOST LIKELY diagnosis is:
Rubella causes low-grade fever with tender postauricular and occipital nodes and a rash that starts on the face, not a high fever that ends before the rash.
Fifth disease starts with bright slapped cheeks and a lacy rash on the limbs in a school-age child, usually with little fever.
In measles the rash appears while the fever is still high, after cough, coryza, and conjunctivitis, and spreads down from the face in an ill child.
Three days of high fever in a well-appearing child under 2, followed by a pink truncal rash as the fever breaks, is roseola from HHV-6 or HHV-7.
A newborn has a flat, sharply demarcated red-purple patch covering the forehead and upper eyelid on the left side. Which evaluation is MOST important?
Liver ultrasound is the screen for infants with five or more cutaneous hemangiomas, not for a facial capillary malformation.
A port-wine stain over the forehead and upper eyelid (the V1 area) raises concern for Sturge-Weber syndrome, so the eye pressure must be checked for glaucoma, along with neurologic assessment.
Propranolol shrinks proliferating infantile hemangiomas, which are raised and appear after birth; it is not used for a flat port-wine stain present at birth.
Fading by early childhood describes a salmon patch on the nape or glabella; a port-wine stain is a capillary malformation that persists and darkens.
On day 9 of an amoxicillin course, a 3-year-old develops urticarial plaques with dusky centers, fever, and swollen, painful ankles. The oral mucosa is normal. The MOST LIKELY diagnosis is:
Urticarial plaques with dusky centers, fever, and painful swollen joints 1 to 3 weeks into a beta-lactam course are a serum sickness-like reaction, which settles once the drug is stopped.
Stevens-Johnson syndrome involves mucosal erosions and blistering with skin detachment; normal oral mucosa argues against it.
Erythema multiforme has fixed target lesions, is most often triggered by herpes simplex, and does not cause arthritis.
IgE-mediated reactions begin within minutes to an hour of a dose and do not cause joint swelling.
School staff find live head lice on a 7-year-old. Which guidance is MOST appropriate?
Lice die within about 1 to 2 days off the scalp, so long exclusion and bagging items for weeks add burden without benefit.
Head lice are a nuisance, not a health hazard, so the child finishes the day, is treated at home, and returns; AAP guidance discourages exclusion and no-nit policies.
Only people with live lice are treated; mass treatment of a class exposes healthy children to pediculicides for no benefit.
No-nit policies keep children out of school needlessly, because nits remain on the hair after effective treatment and do not mean active infestation.
A 7-year-old has a 3-day-old sutured forearm laceration with 1 cm of surrounding erythema and tenderness, no fluctuance or drainage, and no fever. Which is MOST appropriate?
Opening and packing the wound is for an abscess with pus or fluctuance, which this wound does not have.
IV therapy is for systemic illness, rapid spread, or failure of oral treatment, not for a well child with 1 cm of erythema.
Spreading redness and tenderness around a sutured wound without pus, fluctuance, or fever is early nonpurulent cellulitis, treated with an oral antistaphylococcal and antistreptococcal agent and a 48-hour check.
A topical antibiotic for a week treats superficial impetigo-like infection but cannot reach cellulitis in the dermis.
A 16-year-old female who is sexually active is starting isotretinoin for nodular acne. Which contraception counseling is correct?
Stopping a week after the last dose is too early; the drug and its effect on a pregnancy last about a month.
Isotretinoin causes severe birth defects, so the iPLEDGE program requires a patient who can become pregnant to use two effective methods together from at least 1 month before the first dose until 1 month after the last.
Six months after is the wrong tail for isotretinoin, and a single method still falls short of the two-method requirement.
One method alone carries its own failure rate, and starting it at the first dose leaves no protected lead-in month.
A 6-year-old has a 3-cm round patch of scaly hair loss on the scalp with broken hairs at the surface and tender posterior cervical nodes. A KOH preparation of plucked hairs shows spores. Which treatment is MOST appropriate?
Topical azoles treat tinea corporis but do not penetrate the hair follicle, so scalp infection persists.
Medicated shampoo reduces spore shedding and is a useful add-on for the child and family, but it does not cure tinea capitis by itself.
Tinea capitis lives inside the hair shaft, so it needs an oral antifungal such as griseofulvin, given for at least 6 weeks and until the scalp clears; terbinafine is an alternative for Trichophyton.
An antibacterial treats the tender nodes and scale as a bacterial infection; the KOH finding shows a fungal cause.
A healthy 5-year-old has 12 small, firm, pearly, dome-shaped papules with central umbilication on the trunk, a few with mild surrounding eczema. The child is otherwise well. The parents ask what to do. Which is the MOST appropriate response?
Molluscum contagiosum is a self-limited poxvirus infection that usually clears on its own over months to a couple of years; treatment is optional and chosen for symptoms or cosmetic concern.
Umbilicated, pearly papules are a poxvirus infection, not a dermatophyte, so an antifungal cream does nothing for them.
Children with molluscum attend school and swim; covering lesions and not sharing towels is enough, and exclusion is not advised.
A potent steroid does not clear molluscum, and on facial or thin skin it adds atrophy risk; the surrounding eczema needs only routine skin care.
A 4-month-old has had intensely itchy papules for 2 weeks, with burrows on the palms, soles, and axillae. Both parents have also started to itch at night. Which plan is MOST appropriate?
Oral ivermectin is not used in infants under about 15 kg, so it is not the treatment for a 4-month-old.
Treating the itch alone misses the mite; without a scabicide for the infant and contacts, the family keeps reinfesting one another.
Itchy papules with burrows on the palms, soles, and axillae and itching relatives point to scabies; permethrin 5% cream is used from 2 months of age, applied to the whole body including the infant's scalp and face, and all household contacts are treated at the same time.
Lindane is neurotoxic and is not used in infants; it is a last-line agent with a boxed warning.
A running total sits here; it fills in after your last pick.
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Descriptions that point the wrong way
A hemangioma left to watch. Most involute, but those that threaten vision, airway or function, or sit on the face in large segments, need referral early, ideally by 1 month of age (AAP hemangioma guideline, 2019).
Every diaper rash as irritant. Irritant dermatitis spares the skin folds; candida involves them and adds satellite papules.
Cradle cap read as eczema. Infant seborrheic dermatitis is greasy and scalp-first; atopic dermatitis in infants itches, involves the cheeks and extensor skin, and usually spares the diaper area.
Keeping a child with fifth disease home. By the time the slapped-cheek rash appears, parvovirus B19 is no longer contagious.
Pityriasis rosea without a second thought. The herald patch and fir-tree pattern are typical, but in a sexually active teen with palm or sole lesions, secondary syphilis belongs on the list.
Impetigo always needing pills. Limited lesions are treated topically; oral antibiotics are for many lesions or outbreaks (IDSA skin infection guideline, 2014).
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Skin conditions owned elsewhere
Adult skin disease is family NP content; childhood rashes are handled here for every exam on the site. NICU skin care is neonatal NP material, with a few items in the NNP-BC practice test. Food allergy and anaphylaxis, even when hives are the first sign, are on ENT and allergy.