Case 32 Flashcards
Acute urticaria case:
5 yo F with family hx of atopy who presents with an evanescent rash on her arms, legs and trunk that is sometimes pruritic. On PE, the rash is erythematous and slightly edematous. There are multiple plaques with surrounding clearing and some wheals. Patient advised to avoid potential allergens, and given antihistamine for symptomatic relief.
Seborrheic dermatitis case:
3 mo F evaluated for scalp lesion. PE reveals waxy yellow scale and mild erythema.
Followed for acne:
16 yo M. Despite trying OTC benzoyl peroxide and prescription tretinoin and clindamycin, he still has open and closed comedones, papules and pustules. He is given a prescription for a three-month trial of doxycycline.
Chronic contact dermatitis:
13 yo M with a three week history of rash below his belly button. On PE, a raised, erythematous, scaly plaque, about 4 cm in length, and 2-3 cm in width is noted in periumbilical region. It appears that he is allergic to the nickel in the buttons of his new jeans. Given appropriate counseling.
Lice:
Girl with history of severe eczema recently exposed to lice. Mother wants to know if she should pick up daughter from school and bring her in from treatment right away. Suitable counseling regarding etiology and treatment of lice.
Scabies:
13 month old male who developed a rash over the past week. PE reveals pustular eruption on his trunk, palms and soles. Further questioning reveals that Johnny and both his parents have been itchy. Exam reveals linear lesions between the mothers liners and along the father’s abdomen. The family is diagnosed and given permethrin.
Ringworm:
Young mother worried about ringworm in her child and her horse recently having worms too. Etiology and treatment of ringworm is discussed, and the student learns about the other forms of tine as well.
What is the classification of mild acne?
Comedonal acne with perhaps a few papules or pustules.
What is the classification of moderate acne?
Significant inflammatory lesions that may leave scars.
What is the classification of severe acne?
Nodulo-cystic type carries an even higher risk for significant scarring.
Pediculosis capitis (lice):
- Commonly seen among school children because of close personal contact and shared belongings
- Not related to personal hygiene habits
- Nits are the egg cases of lice. They are firmly attached to the hair shaft 1-2 mm from the scalp and difficult to remove.
Scabies:
- Classic lesion: 5-10 mm linear thread-like lesion (the burrow, or molting pouch)
- Often difficult to diagnose in infants because of its atypical appearance
- Common. Infection has nothing to do with cleanliness.
- Caused by a mite called Sarcoptes scabiei
- Acquired by significant close physical contact and through fomites (bedding, clothes)
- Pruritis caused by mite burrowing into the skin to lay eggs
- Most intense time of itching is at night
- Common distribution sites: Wrists, elbows, fingers and toes
- Definitive diagnosis relies on the identification of mites, eggs, eggshell fragments, or fecal pellets:
- -Superficial skin samples should be obtained from characteristic lesions by scraping laterally across the skin with a blade
- -Specimens can be examined with a light microscope under low power with mineral oil
Tinea corporis
Ringworm
Tinea pedis
Athlete’s foot
- More common in young adults than children
- Usually appears scaly, with cracks and fissures between the toes
Tinea versicolor
- Infection with the yeast form of a fungus (Malassezia globosa), part of normal skin flora
- May be contagious
- Excess heat and humidity predispose to infection
- Pink, brown or white lesions with fine scale
- Changes color
- Recurrences common, may take months for pigment changes to return to normal
Tinea capitis
“ringworm of the scalp”
- Slow-growing fungus in hair follicles
- Kerion: An inflamed, weeping boggy lesion caused by a significant allergic response to the fungus
Warts
Verrucae
-Caused by human papillomavirus (HPV)
Mulloscum contagiosum:
- Caused by mulloscum contagiosum virus
- Lesions are small, smoother than common warts, and may have a central dimple (“umbilicated”)
What are five different causes of diaper rash?
- Irritant dermatitis
- Diaper candidiasis
- Bacterial infection
- Zinc deficiency
- Langerhans cell histiocytosis
Irritant dermatitis:
- Most common diaper rash
- Due to prolonged exposure to moisture, friction and/or digestive enzymes (worse with diarrhea)
- Irregular areas of erythema with skin maceration on convex surfaces of the skin
- Typically spares the intertriginous creases
Diaper candidiasis
Erythematous papules that become confluent, bright red plaques surrounded by more erythematous papules (satellite lesions)
Bacterial infection cause of diaper rash:
- Less common
- Usually in perianal area
- Often caused by Group A Strep (Step pyogenes)
- Potentially serious, leading to cellulitis and even dissemination via bacteremia
- Infant may be irritable
- May see streaks of blood on stools
Zinc deficiency
- Infrequent cause of significant diaper rash
- May result from either nutritional deficiency (acrodermatitis enteropathica) or malabsorption (cystic fibrosis).
Langerhans cell histiocytosis
- Crusty, weepy lesions that may bleed
- Biopsy required for diagnosis
What are primary lesions?
Macule, Patch, Papule, Plaque, Vesicle, Bulla, Pustule, Nodule, Wheal, Telangectasia, Petechiae, Purpura
What are secondary lesions?
Scale, Crust, Fissure, Erosion, Ulcer, Excoriation
Macule:
Flat, circumscribed discoloration (eg, freckle) Less than or equal to 1 cm.
Patch:
Larger, flat lesion of color change of the skin. Greater than 1 cm.
Papule:
Elevated, circumscribed solid lesion (eg, mole). Less than or equal to 1 cm.
Plaque:
Broad, elevated lesion; may represent a confluence of papules. Greater than 1 cm.