32: 5-year-old female with Rash

Question 1

Dermatology Terminology

Answer 1

• type
• arrangement
• location
• pattern of distribution
• progression over timee

Question 2

Characteristics of Primary Lesions

Answer 2

-macule
-patch
-papule
-plaque
-vesicle
-bulla
-pustule
-nodule:
Majority of a nodule is below the skin
-wheal
-telangectasia: A dilation of superficial venules, arterioles, or capillaries visible on the skin
-petechiae-dont blanch w pressure
-purpura-dont blanch with pressure

Question 3

Characteristics of Secondary Lesions

Answer 3

• scale: Flakes of keratin that can be fine or coarse, loose or adherent.
• crust: Dried remains of serum, blood or pus overlying involved skin.
• fissure:Linear, often painful cleavage in the surface of the skin.
• erosion
• ulcer: Depressed lesion extending into the dermis or subcutaneous tissue. May lead to scar formation.
• excoriation: Traumatized, superficial loss of the skin, often linear, caused by scratching or rubbing.

Question 4

Atopic History: A family history including any or all of the following conditions called the atopic triad:

Answer 4

• atopic dermatitis (eczema)
• asthma
• allergic rhinitis (hayfever)

Question 5

Acute Urticaria (Hives)

Answer 5

A rash that comes and goes-changing almost as one watches-is very consistent with acute urticaria, also known as hives.

Often hives are caused by a histamine release triggered by allergens like drugs, foods, or pollen. The underlying cause can include viruses and even temperature. The offending trigger or agent can’t always be determined.

Question 6

Hive Treatment

Answer 6

1. Avoid suspected allergens
2. Symptomatic treatment:
   - -Over-the-counter antihistamines (e.g., hydroxyzine, loratidine or cetirizine; these are related to diphenydramine [Benadryl] but are less sedating).
   - -A course of oral prednisone is rarely used if antihistamines don’t control the symptoms. (Topical steroids don’t seem to be as effective, especially since hives can occur all over the body, be transient, and cover large areas.)
   - -Keep patient cool and calm (try cool, soothing baths; heat will worsen the itching).

Question 7

The Stages of Acne

Answer 7

open comedones (blackheads) or
closed comedones (whiteheads).

Question 8

The following are known to exacerbate acne lesions:

Answer 8

Make-up (unless noncomedogenic) Mechanical factors such as manipulation) Occlusion, as occurs with some sports gear Overzealous cleaning

Question 9

Chronic Nickel Contact Dermatitis

Answer 9

• -This fairly common skin condition (view photo) is an example of a delayed type IV hypersensitivity reaction.
• -The reaction requires sensitization, so onset is usually within 24-72 hours from the start of contact.
• -These reactions can occur despite prior tolerance to exposure.
• -Development of a rash depends on whether or not the skin barrier is intact or damaged.
• -The rash often resolves within days to weeks of avoidance.
• -If the allergy is difficult to control, some will refer to an allergist to consider “patch testing” to evaluate for nickel or other allergen leading to allergic contact dermatitis.

Question 10

Acute Contact Dermatitis

Answer 10

Unlike chronic reactions, acute reactions tend to have vesicles, edema, and erythema. They are also extremely pruritic.

Common causes are plants in the toxicodendron (or Rhus) genus, such as poison ivy, poison oak, and poison sumac.

Question 11

Topical steroids potency

Answer 11

Mild
Class 6 & 7
hydrocortisone acetate, 1% (OTC)

Intermediate
Class 4 & 5
triamcinolone acetonide, 0.1%

Potent
Class 2 & 3
betamethasonedipropionate, 0.05%

Super Potent
Class 1
clobetasol propionate, 0.05%

(The class 1 agent clobetasol, 0.05%, is approximately 1000 times more potent than over-the-counter hydrocortisone,1%)

Question 12

There are many potential side effects of topical steroid use. The most important are:

Answer 12

Skin atrophy
Telangiectasias
Hypopigmentation
Suppression of the hypothalamic-pituitary axis

Question 13

Treatment of Pediculosis Capitis (Head Lice)

Answer 13

• first-line treatment is 1% permethrin lotion, available in the U.S. without a prescription. Permethrin has very low toxicity, but may require two or three repeated applications in weekly intervals to achieve full effect. Pediatric providers should be aware of local resistance patterns
• Benzyl alcohol 5% (for children >6 mo) or malathion 0.5% (for children 2 yo or older) can be used in areas where resistance to permethrin or pyrethrins has been demonstrated or for a pt w/ a documented infestation that has failed to respond to appropriately administered therapy with permethrin or pyrethrins.
• Lindane 1%, formerly the tx of choice, is no longer recommended for use because of known neurotoxicity to humans. In addition, there is widespread resistance.

Question 14

Scabies presentation

Answer 14

• The scabies mite causes itching because it burrows into the skin and lays eggs.
• The most intense time of itching is often at night.
• Wrists, elbows, fingers, and toes are among the common distribution sites for scabies.
• The most classic lesion for scabies is about a 5-10 mm curvilinear thread-like lesion–the burrow; but infants often do not have burrows on presentation.

Question 15

Scabies Tx

Answer 15

• -two applications of permethrin 5% cream, 1 wk apart, for all affected household members.
• -The cream is applied at night before bed and washed off in the morning, or after around 8-12 hours.
• -Adults should apply the cream from the neck down.
• -For infants, the entire body should be covered from the hairline down, including behind the ears, being careful to avoid the areas around the eyes and mouth.
• -After bathing, wash all bed linens and clothing worn during treatment.
• -Itching (known as “post-scabetic itch”) may persist for a few wks after the mites have been killed and is due to persistent inflammation from the infestation. A moderate potency topical steroid and over-the-counter diphenhydramine may be helpful.
• -Sometimes families need to be re-treated or discover there was another hidden exposure.

Question 16

Characteristics of Ringworm: Appearance

Answer 16

The classic lesion of ringworm of the body (tinea corporis) is an annular, well-circumscribed, scaly plaque with a raised border and a center that is brown or hypopigmented.

Question 17

Other Types of Tinea: Tinea Pedis

Answer 17

As its name implies, it is found on the feet (also known as “athlete’s foot”).

Question 18

Other Types of Tinea: Tinea Versicolor

Answer 18

• actually an infection with the yeast form of a fungus (Malassezia globosa as well as other malassezia species) that is part of normal skin flora.
• First-line treatment is selenium sulfide lotion.

Question 19

Other Types of Tinea: Tinea Capitis

Answer 19

• -This is ringworm of the scalp.
• -Systemic therapy is required for this type of tinea; topical treatment is usually not successful because the hair follicles are deeper on the scalp.
• -While many oral antifungal agents have been developed, griseofulvin is still the treatment of choice.
• -Because the fungus grows slowly and is killed in the replication phase, it needs to be treated for an extended period of time–usually six to eight week; treatment should continue after it appears better to prevent recurrence.
• -Occasionally, there are resistant strains or a child who does not tolerate griseofulvin; for these cases, alternative therapies include terbinafine and itraconazole.
• -With tinea capitis, be on the watch for a significant allergic response called a “kerion” (an inflamed, weeping, boggy lesion that often requires treatment with oral steroids; although once the fungal infection in under control, the reactions go away).

Question 20

Common Warts vs. Molluscum Contagiosum

Answer 20

Warts are commonly caused by one of the human papillomaviruses (HPV).

Molluscum contagiosum, another virus, causes a similar skin condition. These lesions are small, smoother than common warts, and many have a central dimple, making them “umbilicated.”

Question 21

Common Etiologies of Diaper Rash: Irritant Dermatitis

Answer 21

–Most common cause of diaper rash.
–Due to prolonged exposure to moisture, friction, and digestive enzymes (worse with diarrhea).
–Presents as irregular areas of erythema with skin maceration on the convex surfaces of the skin
–Typically spares the intertriginous creases.
Treatment
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Question 22

Common Etiologies of Diaper Rash: Diaper Candidiasis

Answer 22

• -Starts off as erythematous papules that become confluent, bright red plaques.
• -The inflamed plaques are surrounded by more erythematous papules called “satellite” lesions.

Treatment:
The anti-fungal medication nystatin is effective against candida and is probably the most often used as it is approved for all ages by the FDA. Imidazole antifungals such as miconazole and ketoconzole can also be effective, but some of these products are not approved for use in infants.

Question 23

Common Etiologies of Diaper Rash: Bacterial Infection

Answer 23

• -A bacterial infection, especially of the perianal area with GAS (S. pyogenes) is another, less common, cause of diaper dermatitis.
• -This can be potentially serious, leading to cellulitis and even dissemination via bacteremia.
• -These infants may also be irritable and have streaks of blood on their stools.

Treatment
Standard treatment with oral antibiotics is effective.

Question 24

Diaper Rash as Presentation of Another Illness

Answer 24

• zinc deficiency

- Langerhans cell histiocytosis

Question 25

Acne is divided into three categories based on the type(s) of lesions present:

Answer 25

Mild
Comedonal acne with perhaps a few papules or pustules mixed in

Moderate
Significant inflammatory lesions with concern for scarring

Severe
Nodulo-cystic type, with an even higher risk for significant scarring

Question 26

mild acne tx

Answer 26

–For very mild cases, many physicians use OTC benzoyl peroxide (BPO) as a good starting point. (However, if a patient is coming to see a physician about acne, he or she usually needs something stronger.)
–BPO is available as a gel or as a skin wash.
–Retinoids (e.g., tretinoin [Retin-A] or adapalene [Differin]) work by normalizing follicular keratinization and are considered the drugs of choice for comedonal acne.


Question 27

moderate acne tx

Answer 27

–For anything other than mild acne, the same initial treatments should be used with the addition of another product. (This management strategy should be familiar to you, as pediatricians often use step- wise evaluation and management plans.)
–Antibiotics can be an important adjunct in the treatment of acne.
–BPO can be combined with a topical antibiotic like clindamycin or erythromycin (antibiotics active
against P. acnes), each agent addressing a different cause for the acne.
–Topical prescription products exist in combination form or may be used in combination.
–Options for oral therapy include antibiotics such as doxycycline or tetracycline, or contraceptive pills (for females).

Question 28

severe acne tx

Answer 28

• Pts with severe acne should be referred to a dermatologist.
• If all other txs have failed or haven’t been tolerated, many dermatologists will then use oral isotretinoin.
• This medication carries significant risks and it is regulated very strictly by the federal gov

Question 29

Timing of treatment with retinoids is important:

Answer 29

• -Retinoids need to be used at night, because they can cause photosensitization and lead to a significant sunburn.
• -Tretinoin is also inactivated by oxidation of BPO (so the BPO cream should be applied in the morning).
• -Tretinoin also must be applied to bone-dry skin or it may be significantly irritating.
• -It is important to make sure teens know that retinoids can make acne transiently look worse.

Question 30

Treatment of Warts

Answer 30

• observation
• salicylic acid
• duct tape
• liquid nitrogen
• cantharidin
• candidal Ag therapy (immunotherapy)
• dig out w/ knife (curettage)

Question 31

The following findings in a patient’s history would point toward an allergic reaction:

Answer 31

• -FHx of atopy
• -Recurrent rapid onset and resolution of rash (suggesting an acute, repeated response to some type of trigger)
• -Pruritis (Pruritis is a helpful clinical feature as it generally rules out diagnoses such as viral exanthems. The pruritis is likely due to histamine release from mast cells during an allergic inflammation.)
• -H/o a therapeutic response to administration of antihistamine is also helpful

Question 32

Differential Diagnosis of Rash



Answer 32

-urticaria d/t T1HSR: Classic lesion is an intensely pruritic, circumscribed, raised, erythematous wheal, often with central pallor.
-papular urticaria: d/t insect bites
-Strep infection
-erythema multiforme: Most commonly caused by herpes simplex infections, but may be associated with medications.
-drug eruption:
May be Type 1 hypersensitivity reactions or may result from non-immunologic triggers of mast cell release (such as from opiates or NSAIDs).
-roseola (HHV6): A viral exanthem that classically follows 3-5 days of a febrile illness.
-erythema infectiosum (5th dz): Rash starts on the face with a “slapped”-cheek appearance followed by a reticular (lacy) erythematous rash on the trunk and extremities.
Caused by parvovirus B19.
-erythema migrans: Lesion associated with early localized Lyme disease.

Question 33

Differential Diagnosis of Rash in an Infant

Answer 33

• Seborrheic dermatitis (cradle cap)
• eczema or atopic dermatitis: A positive history of atopic diathesis would support this diagnosis.
• candidal rash: Commonly manifests as a diaper dermatitis peaking between 7-10 months of age.
• psoriasis

Question 34

Differential Diagnosis for Pustular Conditions: Staph

Answer 34

–Staphylococcal folliculitis, furunculosis: Can be very similar to nodular or cystic acne.
Often below waist or in groin area.

Question 35

Differential Diagnosis for Pustular Conditions: Acne vulgaris

Answer 35

Due to several processes:

• -Keratinous material and excess sebum (due to androgenic influence) plug the pilosebaceous gland.
• -Increased sebum provides a growth medium for superinfection with Propioniobacterium acnes.

Question 36

Differential Diagnosis for Pustular Conditions:: Hidradenitis suppurativa

Answer 36

–Pustular lesions caused by occlusion of the apocrine follicular units (instead of the pilosebaceous units).
–Often superinfected with Staphylococcus aureus or Streptococcus pyogenes.
–Areas most likely affected in women:
Axillae, Groin, Inframammary regions
–In men:
Perineal and perianal areas more commonly affected.

Question 37

Differential Diagnosis for Pustular Conditions: Rosacea

Answer 37

• -More often seen in adults.
• -“Early” form seen in adolescents is characterized by inflammatory papules and micropustules, and redness.
• -No comedones.
• -Worsens with alcohol, spicy food, temperature extremes, and stress.
• -Can be treated with topical metronidazole and various other medications.

Question 38

Differential Diagnosis for Pustular Conditions:: Perioral dermatitis

Answer 38

• -A variant of rosacea also commonly seen in adolescents, and treated the same way.
• -See erythema, scaling, and papules or pustules, but no comedones.
• -“Perioral” almost a misnomer, as this may be seen around the mouth, nose, or eyes.

Question 39

Differential Diagnosis of Ringworm: Nummular eczema

Answer 39

• Consists of coin-shaped lesions commonly on the legs and buttocks.
• Has an annular configuration and scaly appearance like tinea.

Question 40

Differential Diagnosis of Ringworm: Psoriasis

Answer 40

–Commonly presents with erythematous papules and plaques with a thick silver scale. –May also have an annular configuration that could be mistaken for tinea.
–A chronic disease.


Question 41

Differential Diagnosis of Ringworm: Pityriasis alba

Answer 41

• -A nonspecific dermatitis characterized by patches of hypopigmentation on the face, neck, upper trunk, and proximal extremities.
• -Lesions range from 0.5 to 5 cm in diameter with well-defined, irregular borders and fine scale.
• -Associated with sun exposure.
• -May be mistaken for tinea versicolor.

common in children 3 to 16 years of age, presents as hypopigmented macules. They most often occur on the face, neck, trunk, and extremities. They have irregular borders, can vary in size, and may have a slight scale. Lesions may become more noticeable after sun exposure because of tanning of the surrounding skin. The etiology of this disorder is unknown, but ultrastructural examination of epidermal cells reveal decreased number of active melanocytes as well as decreased number and size of melanosomes.

Question 42

Differential Diagnosis of Ringworm: Pityriasis rosea

Answer 42

• -Characterized by scaly papules and plaques in the hallmark “christmas tree” distribution on the back and trunk, following the lines of skin cleavage.
• -Lesions may also be found on the upper thighs and in the groin area.
• -The initial lesion, called the “herald patch,” is usually the largest scaly plaque with a raised border and can easily be confused with tinea corporis.

Question 43

A 3-year-old male presents to clinic with an annular, well-circumscribed, scaly plaque with a raised erythematous border and central hypopigmentation on the left thigh. The mother reports that the lesion is highly pruritic and that the patient has been exposed to other children with a similar rash at day care. Upon further examination, a similar lesion with boggy borders is also found on the posterior aspect of his scalp. Which of the following is the most appropriate treatment for this child’s problem?

Answer 43

Topical antifungals are not usually successful in treating tinea capitis, because the infected hair follicles are deep within the scalp. Systemic griseofulvin is the first choice for the treatment of tinea capitis

Treatment with hydrocortisone cream will worsen the fungal infection.

Although topical antifungal therapy would be appropriate for the lesion on the leg (tinea corporis), involvement of the scalp (tinea capitis) necessitates systemic antifungals

Question 44

A 3-year-old child is found to have a dry, pruritic rash on his face. Physical exam is notable for confluent areas of erythema and scaling. There are mild excoriations surrounding some areas and mild lichenification of the extensor surfaces of both elbows. What is the next best step in management of this child’s problem?

Answer 44

Atopic dermatitis most often presents with dry, itchy skin in addition to erythema, scaling, vesicles, or lichenification in skin flexures. Treatment consists of emollients and topical corticosteroids

Question 45

permethrin cream

Answer 45

Scabies is characterized by papules or vesicles accompanied by severe pruritis, especially at night. In addition, burrows may be evident. The wrists, ankles, palms, soles, interdigital spaces, axilla, waist, and groin are among the most common locations for lesions. Finally, there is often a positive sick contact history with similar symptoms.

Question 46

Hyperproliferation of keratinocytes

Answer 46

Psoriasis can present in a variety of ways, but most commonly presents as a plaque. Plaques are often located on the scalp, external ear, and extensor surfaces presenting as a thick silvery scale and sharply demarcated borders. It may or may not be pruritic.