Week 5 Flashcards
A 40 year old women comes to your clinic with a pedunculated, red papule on her finger. She said it appeared “quite suddenly” a few weeks ago and has gotten bigger. It bleeds easily when touched. What is the most likely diagnosis?
A) Cherry angioma
B) Pyogenic granuloma
C) Hemangioma
D) Acrochordons
The correct answer is B, pyogenic granuloma. This benign neoplasm is described as an eruptive, red, and raised papule that bleeds easily with trauma. They are usually solitary and can be sessile or pedunculated.
A is incorrect. Cherry angiomas are shiny bright red papules but they do not bleed. They can be found anywhere on the body and usually multiple papules are seen.
C is incorrect. Hemangiomas are raised, red, plaques that grow in size, but they are usually seen in young children at birth or within the first few weeks of life. They are easily compressed and usually disappear spontaneously.
D is incorrect. Acrochordons or skin tags are fleshy papules that are often pedunculated. However, they are usually skin colored to brown (not red) and are usually found in the axillae, neck, groin, and eyelids.
SM 254a Benign Neoplasms
Learning objective: 1. Describe clinical features of the most common benign skin neoplasms and reassuring signs to distinguish them from malignant skin neoplasms (MKS1d)
Which cell type in the epidermis presents antigens to T lymphocytes and helps limit allergic contact dermatitis reactions?
A) Melanocytes
B) Merkel cells
C) Mast cells
D) Langerhans cells
E) Macrophages
The correct answer is D) Langerhans cells. Langerhans cells are dendritic cells in the epidermis that are antigen-presenting cells that direct the immune response. They can initiate an immune response or help induce tolerance to contact allergens.
A is incorrect. Melanocytes are found in the basal layer of the epidermis but their function is to synthesize melanosomes full of melanin that is secreted into keratinocytes. The melanin absorbs UV radiation from the sun to prevent DNA damage and production of free radicals.
B is incorrect. Merkel cells are also found in the epidermis but are mechanoreceptors that sense light touch. They synapse with nerve endings in the basal layer of the epidermis.
C is incorrect. Mast cells are important members of the immune system involved in acute hypersensitivity reactions in the skin where they can release heparin and histamine containing granules. However, they are found in the dermis.
E is incorrect. Macrophages are phagocytic antigen-presenting cells. However, they normally are found in the dermis and their function is to clear debris and contribute to matrix remodeling during wound healing.
SM 255a Structure and Function of the Skin
Learning Objective: Explain the character and function of the other major cell types residing in the epidermis.
A 15 year old patient presents to the clinic with mild atopic dermatitis on her neck and wrists. The areas are dry and itch infrequently. What should be the first line of treatment?
A) Topical steroids
B) Topical tacrolimus
C) Light therapy
D) Dupilumab
The correct answer is A) topical hydrocortisone. For mild atopic dermatitis, the first line of treatment is low-potency topical corticosteroids once daily on the affected areas along with using emollients liberally, with follow-up in 2-4 weeks.
B is incorrect. Topical calcineurin inhibitors like topical tacrolimus should be tried if there is no improvement after treatment with topical corticosteroids.
C is incorrect. Light therapy should be used in older children and adults after medium to high potency topical corticosteroids and topical calcineurin inhibitors have not led to improvement.
D is incorrect. Dupilumab is a novel treatment for atopic dermatitis that can be considered in adults and children greater than 12 years of age instead of systemic immunosuppressants. Similarly, this is an option if topical corticosteroids and topical calcineurin inhibitors have not led to improvement.
SM 256a Eczema and Itchy Skin
Learning Objective: Design a treatment plan for patients with atopic dermatitis. MKS 1e
A 30 year old man presents to your dermatology clinic with a “Christmas” tree pattern of oval salmon colored macules on his back that first appeared 3 weeks ago after he had a cold. What is the most likely cause?
A) inflammation due to overexpression of cytokines (e.g. TNF-alpha)
B) Reactivation of Human herpesvirus 6 or 7
C) Streptococci infection
D) Yeast on the skin
The correct answer is B. The patient’s clinical description best matches that of pityriasis rosea. This self-resolving disorder is due to a possible reactivation of HHV 6 or 7 that are latent in mononuclear cells.
A is incorrect. Psoriasis (thick plaques with silver scale) is an inflammatory skin disease caused by T cells and overexpression of cytokines including TNF alpha, IL-17, and IL-23.
C is incorrect. A bacterial strep infection or viral infection can trigger guttate psoriasis, an eruption of smaller coin sized silver scale plaques.
D is incorrect. Yeast specifically Pityrosporum ovale may cause seborrheic dermatitis, which is characterized by redness and waxy flaking around the nasolabial folds, eyebrows, beard area, ears, hairline and scalp.
SM 257a Papulosquamous Disorders
Learning Objective: Explain how to recognize Seborrheic dermatitis and pityriasis rosea (MKS 1b)
A 28 year old woman has a melanoma lesion with a Breslow thickness of 1.1 mm without ulceration. What is the best next step for the patient?
A) Offer radiation treatment
B) Offer nivolumab
C) Perform a sentinel lymph node biopsy
D) Re-excise the melanoma with 1 cm resection margins and perform a sentinel lymph node biopsy
The correct answer is D. The patient currently has Stage IB melanoma assuming the melanoma is confined to the skin with no lymph node involvement (Breslow thickness >1.0-2.0 mm without ulceration). To assess this, the patient should undergo resection to make sure no melanoma is detected in the surgical margins.1-2 cm margins should be used for lesions up to 2 mm in Breslow thickness. Since the melanoma is greater than Breslow level 0.8 mm a sentinel lymph node biopsy should be done.
A is incorrect. Radiation treatment is not indicated at this stage.
B is incorrect. Adjuvant therapy including nivolumab should be offered if the patient has lymph node involvement, so resections and a sentinel lymph node biopsy should be done first.
C is incorrect. While a sentinel lymph node biopsy is warranted, re-excision of the lesion also needs to be done.
SM 258a Melanoma
Learning Objective: Describe the outcome of melanoma and plan the approach to the patient when a melanoma is suspected.
A 55 year old patient presents to your clinic with a raised pearly papule with telangiectasia on her face.
What is the most likely mutation that led to this disorder?
A) p53
B) CDKN2A
C) Ras
D) PTCH
The correct answer is D. The patient is presenting with nodular basal cell carcinoma (the most common variant seen). Basal cell carcinomas result from inactivation of tumor suppressor gene PTCH from UV exposure.
A is incorrect. Inactivation of the tumor suppressor gene p53 is associated with squamous cell carcinomas, which often present as a scaly or crusted papule that may be ulcerated.
B is incorrect. Inactivation of the tumor suppressor gene CDKN2A is associated with melanoma.
C is incorrect. Activation of the oncogene Ras is also associated with squamous cell carcinomas.
SM 260a Non melanoma Skin Cancer/ Photobiology
Learning Objective: Connect underlying genetic disturbances with the unique, multisystem clinical manifestations of genetic skin diseases.
A 42 year old man presents to your clinic with an itchy, red maculopapular truncal rash that started a week ago. He denies fever, any lesions on mucus membranes, and blistering. He started a course of trimethoprim and sulfamethoxazole a few weeks ago. What is the most likely diagnosis?
A) Exanthematous-type drug reaction
B) Dermatitis herpetiformis
C) Erythema multiforme minor
D) Stevens-Johnson Syndrome
The correct answer is A. The clinical vignette is typical of exanthematous-type drug reactions which are the most common form of drug eruptions. The rash usually occurs within 1 week of initiation of drugs including beta-lactams, sulfonamides, nonnucleoside reverse transcriptase inhibitors, and antiepileptic medications.
B is incorrect. Dermatitis herpetiformis presents as a symmetric, itchy, papulovesicular eruption on extensors, the buttocks and the back. It is associated with gluten-sensitive enteropathy and granular IgA deposits in the skin and not with a reaction to drugs.
C is incorrect. Erythema multiforme minor presents with target lesions and changes in oral mucosa. They are most commonly caused by herpes simplex virus infections and rarely by drug exposure.
D is incorrect. Stevens-Johnson syndrome is a rare, serious adverse cutaneous drug reaction that presents with epidermal detachment and mucocutaneous involvement. SJS is when <10% of the body surface area has epidermal detachment and can be caused by NSAIDS, antibiotics, and antiepileptics. The patient is not showing any clinical features of a severe drug reaction.
SM 261a Drug Reactions/Blistering Disorders
Learning Objective: Describe the clinical features of different types of cutaneous drug reactions.
A 41 year old patient presents with erythematous, macerated skin in the axilla, in the anogenital region, and between his fingers. The areas are surrounded by vesicopustules with collarettes of scale. He reports that he had finished a course of penicillin a few days ago. What is the most likely diagnosis?
A) Tinea Corporis
B) Pityriasis Versicolor
C) Cutaneous Candidiasis
D) Sporotrichosis
The correct answer is C. This fits the clinical presentation of cutaneous candidiasis caused by Candida albicans, which is associated with antibiotic use. Congenital candidiasis, neonatal candidiasis, and diaper dermatitis also present with erythema and satellite pustules. Treatment for cutaneous infection is topical nystatin.
A is incorrect. Tinea corporis presents as pruritic, annular lesions with centrifugal spread (from trunk to extremities) that are seen 1-3 weeks after exposure to the dermatophyte. The groin, palms, and soles are usually excluded.
B is incorrect. Pityriasis versicolor presents as dustlike hypo-pigmented or salmon-colored patches on the trunk and proximal extremities, commonly seen with hot, humid weather.
D is incorrect. Sporotrichosis presents usually on hands or feet as a dermal nodule that becomes a small ulcer. A chain of soft nodules can be seen with lymphatic spread the draining lymph nodes become inflamed. This fungal infection is more common in workers exposed to decaying vegetable matter such as gardeners and forestry workers and is most common in the Midwestern river valleys.
SM 263a Bacterial and Fungal Skin Infections
Learning Objective: Describe the presentation of common cutaneous fungal, bacterial, and mycobacterial infections.
A 37 year old woman presents to your clinic with episodes of flushing on her cheeks, forehead, nose, and chin that started a few months ago. These areas are now erythematous. She describes the skin as sensitive and burning, which gets worse when she’s in the sun or stressed. She reports that her eyes have been more sensitive to light, are dry and she has experienced eyelid crusting. What’s the best treatment for this patient?
A) topical retinoids and topical antibiotics with benzoyl peroxide
B) intralesional glucocorticoids and systemic antibiotics
C) Surgical correction with scalpel or CO2 laser
D) Oral tetracyclines and a topical metronidazole gel
The correct answer is D. The patient is presenting with ocular type rosacea, which is best treated with oral tetracyclines. Ocular type rosacea is seen in around 50% of rosacea patients. There are many treatment options but systemic therapies are often combined with a topical agent.
A is incorrect. Topical retinoids and topical antibiotics with benzoyl peroxide is a proper treatment option for acne. Acne vulgaris does not fit the clinical scenario as well since patients usually have a younger age of disease onset, and present with comedones that can be on the full face and trunk.
B is incorrect. Intralesional glucocorticoids and systemic antibiotics are therapies for hidradenitis suppurativa which presents with tender, red, ulcerated draining nodules with double comedones in axillae, inframammary folds, inguinal creases and medial buttocks.
C is incorrect. Surgical correction would be the best option for the phymatous type of rosacea, which presents with hyperplasia and scarring most commonly on the nose (rhinophyma). Other areas that could be affected include the chin, eyelids, forehead or earlobes.
SM 264a Acne, Rosacea and Related Disorders
Learning Objective: Describe the clinical presentations of acne vulgaris, acne rosacea and perioral dermatitis by identifying different lesion types and distinguishing clinical features. (MKS1d)
Explain the basic principles of treatment for acne vulgaris and acne rosacea. (MKS1b,1e)
Which of the following is not typical of atopic dermatitis in skin of color?
- Melanonychia striata
- More papular or follicular presentation
- Less erythema
- Resolves with hyper and hypopigmentation
The correct answer is A. Melanonychia striata is a normal variation in skin of color. It presents as a longitudinal pigmented, brown to black streak on the nail due to melanocytic activation. It is not associated with atopic dermatitis in skin of color.
B, C, and D are incorrect. They describe the typical clinical presentation of atopic dermatitis in skin of color.
SM 265a Skin of Color
Learning Objective: Recognize conditions common in skin of color.
