Inflamatorias

Question 1

A patient presents with hair loss in a well-defined area that started 3 weeks ago. The patient has no other complaints or significant medical history. On the exam, there is a 2 x 2-centimeter area without hair in the parietal area. The skin is smooth and without erythema. The hairs at the borders of the lesion come out with minimal traction. What is the most probable diagnosis?

1. Tinea capitis
2. Alopecia areata
3. Lichen planopilaris
4. Telogen effluvium

Answer 1

2. Alopecia Areata

Alopecia areata often occurs suddenly in a well-defined area. The cause is autoimmune and it is seen in all age groups. The skin of the involved area appears healthy. The condition rarely progresses to loss of all scalp hair.

Question 2

A 38-year-old male presents with the complaint of dark brown, velvety eruption underneath his armpits. It is neither painful nor itchy. He noticed the eruption a few weeks ago but is not sure if it was always present. He thinks that it is due to staying out in the sun for too much time. He has had a weight loss of 2 kg in the past 2 months but believes that his diet and exercise regimen has helped him reduce his weight. His family history is unremarkable. On examination, his vital signs are blood pressure 120/70 mmHg, pulse 60/min, and a temperature of 97.7F. BMI is 30. What is the next best step in the management of this patient?

1. Topical corticosteroids
2. CT scan of stomach
3. Blood glucose levels
4. Blood creatinine kinase (CK) levels

Answer 2

3. Blood glucose levels

• This 38-year-old male with obesity and acanthosis nigricans (dark brown, velvety eruption underneath his armpits) likely has diabetes type 2 and measuring his blood glucose would be the best next step in the evaluation of this patient.
• Acanthosis nigricans is a skin condition characterized by hyperpigmented, velvety plaques on the skin, most commonly on the neck or axillae although they can be found anywhere on the body including mucous membranes. Acanthosis nigricans typically presents as a hyperpigmented, thickened plaque on the neck or axillae. Other areas such as the inguinal folds and anogenital region are less commonly involved. Early acanthosis nigricans has a rough texture and mild plaque-like elevation that becomes thicker as the lesion progresses. Clinical examination is sufficient for diagnosis (see picture) and biopsy is not needed.
• The clinical recognition of acanthosis nigricans is crucial because it can be associated with an underlying medical condition, especially those that lead to insulin resistance. Diabetes type 2 and obesity are the most common disorders associated with acanthosis nigricans. Less commonly, it can be a sign of an underlying visceral malignancy (eg. stomach cancer). Endocrine disorders causing insulin resistance (eg. polycystic ovary disease, Cushing’s syndrome) can also cause acanthosis nigricans. Rarely, some cases of acanthosis nigricans can be inherited (familial acanthosis nigricans) or present as part of a genetic syndrome. Patients with obesity presenting with acanthosis should be evaluated for diabetes type 2 as there is a very strong correlation between acanthosis nigricans and diabetes type 2. Gastric adenocarcinoma is the most common cancer that can present with acanthosis nigricans and these patients usually do not have obesity.
• Treating the underlying cause has been shown to improve acanthosis nigricans. If due to diabetes and obesity, improvements in acanthosis nigricans have been linked with weight loss and medications that improve insulin sensitivity (eg. metformin). If due to cancer, resolution of acanthosis nigricans can be seen following treatment of the underlying malignancy.

Question 3

A man in his 60s had a cardiac event some weeks ago and was prescribed five new medicines including aspirin, hydrochlorothiazide, metoprolol, quinapril, and nitroglycerin. He presents with an itchy, blistering rash confined to his upper chest, extensor arms and dorsal hands. He attributes the rash to a fishing expedition the previous weekend. What is the most likely cause?

1. It is likely that contaminated sea water is the cause of the rash
2. The rash may be drug-induced photosensitive eczema due to hydrochlorothiazide
3. The rash is lichenoid drug eruption due to quinapril
4. He has discoid eczema unrelated to the fishing expedition

Answer 3

2 - The rash may be drug-induced photosensitive eczema due to hydrochlorothiazide

• Photosensitive eczema presents as an acute or chronic, diffuse or patchy, itchy, dry or blistered rash on areas exposed to sunlight, especially the V of the neck, the forearms and the dorsal hands. Onset of the rash is 24 to 72 hours after exposure.
• Photosensitive eczema is often drug induced. There is a long list of potential culprits of which the most common are nonsteroidal anti-inflammatory drugs, diuretics, antibiotics and antipsychotics. They cause photosensitivity mainly to long wavelength ultraviolet radiation (UVA).
• The rash can be distinguished from endogenous eczema by its distribution, bearing in mind that atopic eczema is sometimes photoaggravated.
• Treatment requires cessation of the responsible drug. As it takes some weeks or months for the sensitivity to settle, measures must be taken to protect against exposure to ultraviolet radiation including avoidance, covering up, and broad spectrum high protection factor sunscreens.

Question 4

A 28-year-old female developed itchy papules on the backs of her hands, her forearms, and anterior chest in the evening after being outdoors for several hours. She reported that a similar rash had occurred on several previous occasions during the spring and summer months despite applying sunscreen products. Which of the following statements are true?

1. Polymorphous light eruption is a more likely diagnosis than solar urticaria
2. She has an 80% chance of carrying a positive antinuclear antibody
3. The most suitable long-term prophylaxis is oral prednisone 20 mg daily for three months
4. This type of rash only affects patients with fair skin (Fitzpatrick skin phototype 1 and 2)

Answer 4

1 - Polymorphous light eruption is a more likely diagnosis than solar urticaria

• Polymorphous light eruption typically presents as groups of irritable erythematous papules or plaques on some areas of skin after sun exposure. It often spares the face and is more common in females than males. Up to 20% of affected patients have a positive antinuclear antibody, usually in low titer, but symptomatic lupus erythematosus is rare.
• The papules or plaques appear several hours after exposure and typically persist for several days. The duration and intensity of exposure triggering the rash are variable. Broad spectrum, high protection sunscreens may delay the onset of the rash.
• Graduated exposure to the sun can prevent the rash. Other prophylactic measures include phototherapy, antioxidants such as beta-carotene and polypodium leucotomos, a one-week course of oral prednisone during summer vacation, and covering up.
• Short-term topical and oral corticosteroids are often prescribed for polymorphous light eruption. Some patients find hydroxychloroquine effective when taken throughout the spring and summer.

Question 5

An elderly gardener has an intensely pruritic chronic rash on his face, neck, and dorsum hands. It spares skin creases and covered skin. The rash is more prominent in summer than in winter. He is on no regular medications. Which of the following treatments are most likely to be effective?

1. A 2-week course of moderate potency topical steroid cream
2. Sun protection factor 50+ sunscreen applied every 2 hours while outdoors
3. Work inside in a greenhouse during the day
4. Azathioprine 150 mg daily

Answer 5

4 - Azathioprine 150 mg daily

• Long-standing chronic photosensitive dermatitis can result in markedly thickened skin, an appearance known as actinic reticuloid. Very brief exposure outdoors or in glasshouses is enough to trigger the reaction in severely affected individuals, who are most often elderly male farmers and gardeners. The provoking wavelength is usually UVA and/or visible light.
• Photosensitive dermatitis is most severe on the areas most exposed to daylight, affecting any skin that is not covered by clothing. The skin creases, skin under the nose and chin, eyelids, interdigital spaces, and skin covered by hair and watch strap are spared.
• Chronic photosensitivity dermatitis rarely improves with topical treatment alone, and sunscreens are rarely adequate to protect against flares. As much as possible, patients should stay indoors away from windows, and cover up fully when outdoors in daylight. This means wearing a broad-brimmed hat, long sleeves, gloves, long trousers, socks, and shoes.
• Immune suppressive drugs such as azathioprine are generally prescribed to reduce the severity of the dermatitis, as it is almost impossible to avoid exposure to the inducing spectrum of electromagnetic radiation.

Question 6

A 27-year-old nurse presents for evaluation of a problem with his hands. He has noticed a worsening red, itchy skin eruption for the last 3 months. He wears multiple pairs of gloves daily and washes his hands over 30 times per day. He has been applying over the counter antifungal cream and hydrocortisone cream twice daily without improvement. Examination reveals erythema and scale on the bilateral dorsal hands and fingers with a line of demarcation at the wrists. A trial of gentle skin care and clobetasol 0.05% ointment twice daily for 6 weeks results in no improvement. Patch testing is performed, and he tests positive for carba mix. What is the next best step in management?

1. Recommend that the patient avoid latex indefinitely
2. Change corticosteroid to betamethasone dipropionate twice daily under occlusion
3. Start narrowband ultraviolet B light therapy 3 times weekly
4. Change work and home gloves to rubber accelerator free products

Answer 6

4 - Change work and home gloves to rubber accelerator free products

• Carba mix represents the carbamates group of rubber accelerators and causes contact dermatitis. There is no evidence that this patient is allergic to latex, which causes contact urticaria, so complete latex avoidance is not required.
• Clobetasol and betamethasone are both Class 1, superpotent topical corticosteroids. Changing to a corticosteroid in the same class is not likely to result in improvement. This patient needs allergen avoidance for improvement to occur.
• Phototherapy would not be indicated prior to a trial of allergen avoidance.
• Carba mix is a common rubber accelerator and the key to the patient’s improvement is avoidance of known allergens.

Question 7

A 6-year-old male presents to the emergency department with a 5-day history of fever and cough with subsequent development of vesicles and small bullae on the arms that spread to the face, lips and oral gingiva. His parents deny any recent medications use, previous oral rashes. What is the next best step in management?

1. Obtain a two-view chest x-ray to assess for atypical pneumonia
2. Prescribe “magic mouthwash” prescription and patient education for “hand, foot and mouth” disease
3. Transfer to a burn center for an obvious case of toxic epidermal necrolysis (TEN)
4. Prescribe oral acyclovir for a “bad case of herpes”

Answer 7

1 - Obtain a two-view chest x-ray to assess for atypical pneumonia

• Our patient demonstrates a pattern consisting of respiratory symptoms followed by a rash, which may be seen in Mycoplasma pneumoniae-induced rash and mucositis (MIRM) or erythema multiforme major.
• The chest x-ray may demonstrate atypical pneumonia to further assess for MIRM as per the currently suggested diagnostic criteria.
• Additionally, serum testing for M. pneumoniae infection may be considered.
• Patients with active pneumonia reasonably should receive organism directed antibiotics. Consultation with an infectious disease specialist or dermatologist may help to direct care.

Question 8

A 15-year-old male presents with his mother, who is concerned about stripes on his back, which she describes as whip marks. She says they have been present for several months. He denies having eaten any shiitake mushrooms or pruritis in the area of concern. What treatment may be effective for this condition?

1. Topical tretinoin
2. Oral antihistamines
3. Topical corticosteroid
4. Dermabrasion

Answer 8

1 - Topical tretinoin

• Rapid truncal growth in adolescence can occasionally result in multiple striae distensae (stretch marks), which are thought to be induced by stretching of the dermis and perhaps related to hormonal factors.
• Although the erythema fades over a year or so, white marks persist long term.
• A careful history is important to exclude other reasons for linear lesions, such as shiitake dermatitis due to undercooked shiitake mushrooms, dermographism (short- lasting weals from scratching) and flagellate erythema due to bleomycin, when undergoing chemotherapy.
• Early striae can be red and are most responsive to treatment. Topical tretinoin has been shown to significantly improve the appearance.

Question 9

Examination of a 67-year-old female complaining of chest pain when climbing stairs reveals yellow plaques over both sets of eyelids. She denies any symptoms associated with the plaques. A familial history includes paternal coronary artery disease and a sibling with the same kind of lesion on her eyelids. Which laboratory test would be most helpful in determining the origin of the lesions?

1. Comprehensive metabolic profile
2. Complete blood count
3. Hepatic profile
4. Lipid profile

Answer 9

4 - Lipid profile

• This patient has xanthelasma palpebrarum, a xanthelasma found on the eyelids.
• Approximately 50% of patients with xanthelasma palpebrarum have hyperlipidemia.
• Decreased high-density lipoprotein may be associated with xanthelasma palpebrarum.
• Xanthelasma are soft or semisolid yellowish deposits that are commonly found along the corners of the upper and lower eyelids. Xanthelasma are not common skin lesions, but when they are observed, they may be a predictor of ischemic heart disease, myocardial infarction, or systemic atherosclerosis. These lesions are often seen in the fourth to fifth decade of life. Once xanthelasma has developed, it will not spontaneously disappear but will remain the same or increase in size. The majority of people come to attention because of cosmetic concerns.

Question 10

A 30-year-old female with multiple sclerosis comes to the clinic complaining of feeling hot for the past 24 hours. She states she has also developed a rash that has spread all over her body. She traveled to Eygpt 4 years ago but has not been back since. She denies any headaches, cough, congestion, muscle aches, or shortness of breath. Three years ago she was diagnosed with multiple sclerosis. Over the past year, she had sharp stabbing pain her jaw and subsequently, she was started on carbamazepine for trigeminal neuralgia one week ago. She is currently sexually active with multiple partners and she uses condoms consistently. Temperature is 102 F and HR is 110. On physical examination, the liver is enlarged and the rash seems to have bullous detachment. Labs show eosinophilia, thrombocytopenia, atypical lymphocytosis, and elevated liver enzymes. Which one of the following is the patient most likely experiencing?

1. Toxic epidermolysis necrosis
2. DRESS syndrome
3. Steven-Johnson syndrome
4. Jarisch-Herxheimer reaction

Answer 10

2 - DRESS syndrome

• Carbamazepine is known to cause numerous dermatologic reactions. One is a drug reaction with eosinophilia and systemic symptoms (DRESS syndrome). This syndrome is characterized by rash, fever, eosinophilia, thrombocytopenia, atypical lymphocytosis, and elevated liver enzymes. These symptoms usually appear with weeks after exposure to carbamazepine.
• Steven-Johnson syndrome is characterized by flu-like symptoms followed by a painful red rash that spreads and blisters. It is less severe than toxic epidermolysis necrosis and skin detachment is less than 10 percent.
• Jarisch-Herxheimer reaction seen in patients with syphilis started on penicillin. It results from the antibiotic destruction of harmful microbes which then leads to endotoxin release. Although this patient is sexually active with multiple partners she states that she uses condoms consistently. There is no history of any penicillin making this answer choice less likely.
• Another dermatologic adverse effect of carbamazepine is toxic epidermolysis necrosis. In this condition, there is necrosis and bullous detachment of the epidermis with surrounding erythema. This can potentially lead to sepsis and patient death. Toxic epidermolysis necrosis is caused by drugs interactions, malignancy, infection, and sometimes vaccinations. It is more severe than Steven-Johnson syndrome, and skin detachment is greater than 30 percent.

Question 11

A 45-year-old female patient with a past medical history of hypothyroidism, breast cancer, and iron deficiency anemia presents to the office complaining of hair loss. The patient states the hair loss started two weeks ago. The hair loss is described as diffuse. A hair pull test is performed from different parts of the scalp, a total of 7 hairs are pulled free. A closer look at the hairs shows a dark bulb at the bottom. What is the most likely type of alopecia in this patient?

1. Anagen effluvium
2. Telogen effluvium
3. Female pattern hair loss
4. Alopecia areata

Answer 11

1 - Anagen effluvium

• Hair pull test of 6 or more hairs is considered a positive test. Anagen effluvium is loss of hair during the anagen phase. This is seen with medication-induced loss, in particular, chemotherapy-induced loss. Class inspection of the bulb will appear dark, indicating the anagen phase.
• Telogen effluvium is diffuse lose in the telogen phase. Inspection of the bulb will reveal a white bulb indicating telogen loss. This occurs following stressful events, pregnancy, surgery, trauma, stress, thyroid disorders, and anemia. A brown or dark bulb indicates the anagen phase.
• Female pattern hair loss is classified using the Ludwig scale. This pattern is frontal sparing loss with most loss in the mid-scalp. It is nonscarring alopecia. Anagen effluvium does not follow a particular pattern and would be more diffuse.
• Alopecia areata is autoimmune nonscarring alopecia. It generally appears as a circular loss of hair. However, a rare form known as alopecia areata incognita can appear diffuse and be confused with telogen effluvium. Anagen effluvium does not present as circular alopecia with a white bulb. Anagen effluvium is diffuse loss with a dark bulb present on a hair pull test.

Question 12

A 65-year-old male presents to the clinic with a painful left great toe. The patient reports he has had a difficult time walking due to the pain. A well-demarcated area of rough, thickened skin is present on the dorsal surface of his left great toe. On closer inspection, a translucent core is present within the lesion. After providing the correct diagnosis, the lesion is treated by parring it. Which of the following is the most likely etiology of the condition?

1. Repeated mechanical stress
2. Viral infection
3. Intrinsic gene mutation
4. Abnormal immune response

Answer 12

1 - Repeated mechanical stress

• Clavus formation is the direct result of repeated mechanical stress to the skin.
• Clavus formation is usually in the form of frictional forces and pressure.
• Physical activity, ill-fitting footwear, and foot deformities causing bony prominences contribute to the development of clavi.
• The removal of trauma to the foot will minimize the chances of clavus recurrence.

Question 13

A 25-year-old man presents with a 6-year history of nodules and pustules on the occipital scalp. Physical examination shows keloidal scarring, sinus tracts, and enlarged follicular orifices which contain clusters of 10 or more terminal hairs. What associated skin condition is most likely to be present in this patient?

1. Cystic acne vulgaris
2. Rosacea with rhinophyma
3. Onychomycosis
4. Dyshidrotic eczema

Answer 13

1 - Cystic acne vulgaris

• This patient has acne keloidalis nuchae.
• Acne keloidalis nuchae is a variant of cystic acne which occurs on the scalp. It occurs almost exclusively in men.
• Patients with acne keloidalis nuchae frequently have cystic acne vulgaris as well. They also have a higher incidence of hidradenitis suppurativa.
• Though rhinophymatous rosacea may have dilated follicular orifices, this condition does not occur on the scalp and it is not associated with hair loss.

Question 14

A 65-year-old male presents with a nodule on the face present for the past three months. On examination, the nodule is soft, well-defined and red-violaceous in appearance. Histopathology reveals subepidermal Grenz zone, inflammatory infiltrate in the dermis, and the perivascular zone. There is also associated leukocytosis. Which one of the following drugs have been reported to be useful in this condition?

1. Etanercept
2. Infliximab
3. Rituximab
4. Secukinumab

Answer 14

3 - Rituximab

• The clinical and histopathology features are suggestive of Granuloma Faciale (GF).
• Granuloma faciale (GF) is a rare, benign, inflammatory skin disease, usually presenting as isolated, well-defined reddish-brown to violaceous asymptomatic papules, nodules or plaques showing follicular accentuation and telangiectasia. Some studies have postulated that GF belongs to a category of IgG4-related sclerosing diseases.
• Rituximab is a monoclonal antibody against CD-20 used in conditions like lymphomas and also dermatological conditions like pemphigus.
• Surgical treatment includes excision with and without grafting. Dermabrasion is a therapeutic choice as well.

Question 15

A patient has a Wagner grade 3 diabetic foot ulcer 30 days after post incision and drainage of abscess and debridement of necrotic tissue. It has not improved. What is the next best treatment?

1. Amputation
2. Hyperbaric oxygen therapy
3. Dynamic compression wraps
4. Split-thickness skin graft

Answer 15

2 - Hyperbaric oxygen therapy

• The current treatment paradigm emphasizes limb salvage if at all possible. Many patients with Wagner 3 diabetic foot ulcers (DFU) will heal and not require amputation as part of their treatment.
• The criterion for hyperbaric oxygen therapy for DFU requires the ulcer to be at least a Wagner 3 which has failed to show significant improvement such as at least 50% smaller size at 4 weeks. Conservative wound care for 30 days includes appropriate antibiotic therapy, debridement, and offloading.
• Dynamic compression wraps are a mainstay of treatment for venous ulcers and are not used to treat DFUs.
• Split-thickness skin grafting is not the first-line treatment for DFU in the acute postoperative period. It is reserved for patients with large and shallow ulcers, in the reepithelialization phase, to decrease the time of ulcer resolution.

Question 16

A 33-year-old G2P1 female presents for her eighteenth week physical. She reports an unknown rash on her arms when her child scratches her that began last week. She notices the rash goes away within thirty minutes after the initial response. She states, “It looks like I’m having an allergic reaction.” She would like to know if this is something that should concern her. Which of the following is the best advice?

1. This is a benign condition commonly seen in pregnant women, especially the second trimester
2. A biopsy is needed to confirm the diagnosis
3. Prescribe her amoxicillin-clavulanate and to follow up in 2 weeks
4. Take epinephrine the next time it happens

Answer 16

1 - This is a benign condition commonly seen in pregnant women, especially the second trimester

• Stressful events like pregnancy most commonly in the second trimester and the onset of menopause have a higher incidence of dermatographism.
• A majority of patients with hypereosinophilic syndrome have dermatographism. It is also seen in atopic children.
• One-third of patients that experience traumatic life events along with psychological co-morbidities experience dermatographism.
• Educate the patient that the condition is harmless to the baby.

Question 17

A patient presents complaining of multiple skin lesions following an untreated upper respiratory tract infection about 3 weeks ago. On physical exam, the lesions appear as erythematous rings with a raised border localized only to the trunk. The patient currently is asymptomatic. What is the most likely cutaneous finding in this patient?

1. Erythema ab igne
2. Erythema multiforme
3. Erythema marginatum
4. Erythema nodosum

Answer 17

3 - Erythema marginatum

• Erythema marginatum is one of the major Jones criteria in acute rheumatic fever.
• Rheumatic fever is an autoimmune condition caused by an infection of group A hemolytic Streptococcus.
• Other causes of erythema marginatum include drugs, infection, allergy, pregnancy, malignancy, or idiopathic.
• With erythema marginatum, it is important to treat the underlying cause of the disease.

Question 18

A 45-year-old female presents to the clinic with a six-month history of hair loss. She states her scalp often itches and burns. On examination, two small alopecic patches are found on the parietal region of her scalp. Mild perifollicular erythema and perifollicular scale are found. Which of the following is the best initial therapy for this patient?

1. Topical tacrolimus ointment 0.03%
2. Minoxidil spray
3. Prednisone
4. Topical clobetasol propionate lotion

Answer 18

4 - Topical clobetasol propionate lotion

• Potent corticosteroids, such as clobetasol propionate, are commonly used in all forms of primary cicatricial alopecia and frequently considered first-line treatments.
• Although topical tacrolimus has been described as an acceptable choice, a low 0.03% topical preparation once a day is unlikely to make a significant therapeutic effect.
• Systemic therapies, like prednisone, are mainly reserved for rapidly progressing or refractory disease.
• Minoxidil helps maximize hair growth of the remaining follicles, but it is not considered a cornerstone for treatment.

Question 19

A 65-year-old man presents to the healthcare provider with an asymptomatic, red-brown, well-defined plaque on the scalp that began one month ago. There is no history suggestive of any other systemic or cutaneous affection. Dermoscopy showed follicular accentuation and telangiectasia. Histopathology confirmed the presence of the Grenz zone beneath the epidermis and leukocytoclastic vasculitis. Which of the following would be the best treatment option in this patient?

1. Topical corticosteroid
2. Topical dapsone
3. Topical tacrolimus
4. Intralesional corticosteroid

Answer 19

3 - Topical tacrolimus

• Granuloma faciale occurs mainly in middle-aged white men. Granuloma faciale should be considered in the differential diagnosis of isolated erythematous plaques on the scalp.
• Dermoscopy can aid in the diagnosis of granuloma faciale. The typical findings on dermoscopy include follicular accentuation and telangiectasia.
• Tacrolimus is a calcineurin inhibitor. Topical tacrolimus has immunosuppressor and anti-inflammatory actions.
• Tacrolimus has shown a good therapeutic effect for granuloma faciale in recent literature. Topical and intralesional corticosteroids showed no or partial healing with no complete clearance in most reported cases. Also, the efficacy of dapsone was demonstrated in a single instance only.

Question 20

A patient presents to the clinic 7 weeks after a flu shot. She claims that 3 weeks after the shot, she felt itching in her upper arm and then developed a rash. She denies any recent infection, travel, or use of medications. Examination reveals a well-defined rash covered with violaceous, shiny papules in a linear distribution approximately 3 cm in length. The provider feels that this is an isomorphic response. Which of the following skin disorders can manifest with such a reaction?

1. Lichen planus
2. Herpes simplex
3. Atopic dermatitis
4. Pityriasis rosea

Answer 20

1 - Lichen planus

• Lichen planus is an inflammatory condition. It may arise de novo or may occur after traumatic insult to the skin such as with any injection. Lichen planus is associated with the Koebner phenomenon (isomorphic response).
• The Koebner phenomenon is the appearance of a new skin lesion following some type of injury.
• The lesion can be reproduced by different methods of injury and has the same clinical features as the patient’s original skin disorder. When caused by scratching, a linear pattern often develops.
• The Koebner phenomenon may occur 3 days to 2 years after the initial injury. Besides psoriasis, one also can see the isomorphic response in patients with vitiligo and lichen planus. Almost any type of skin injury can elicit this reaction.

Question 21

A 36-year-old Asian woman is diagnosed with new-onset partial seizures. The patient’s electronic record documents the presence of the HLA-B*1502 allele. Her vital signs include a blood pressure of 115/77 mmHg, a temperature of 98.5 degrees Fahrenheit, respiration of 14 breaths per minute, and a pulse of 79 beats per minute. Physical examination is unremarkable. The patient is prescribed oxcarbazepine for treatment. Which of the following does the patient have the highest risk of developing because of her treatment with oxcarbazepine?

1. Cushing syndrome
2. Steven-Johnson syndrome
3. Palmar-plantar erythrodysesthesia
4. Erythrodermic psoriasis

Answer 21

2 - Steven-Johnson syndrome

• Oxcarbazepine is structurally similar to carbamazepine, and thus there is an increased risk of developing Stevens-Johnson syndrome or toxic epidermal necrolysis, especially in Asian patients with the HLA-B*1502 allele.
• Oxcarbazepine is indicated for the treatment of partial-onset seizures in adults and children.
• Oxcarbazepine is a prodrug. The active metabolite is 10-monohydroxy (MHD).
• MHD is a sodium channel blocker and it may also modulate calcium channels.

Question 22

A 6-month-old female infant is brought to the clinic with her father. He complains of new onset “whiteheads” and “blackheads” on his daughter’s cheeks. Examination confirms the presence of comedones, along with a few inflammatory papules and pustules. The lesions are distributed on her cheeks and chin as well. There are no signs of hyperandrogenism. The caregiver is to be educated on his daughter’s condition. Which is the most appropriate in terms of the specific diagnosis?

1. In general, many cases have a mild to moderate course, resolving by 1 to 2 years of age without treatment
2. It does not result in scarring
3. Most commonly affects children at 4 to 6 weeks of age
4. Equally common in both sexes, however, it tends to be more severe in males infants

Answer 22

1 - In general, many cases have a mild to moderate course, resolving by 1 to 2 years of age without treatment

• True infantile acne affects the cheeks, forehead, and chin and presents in children approximately six weeks to 1 year of age. Infantile acne affects both sexes, but, unlike acne vulgaris of adolescent patients, it is more common in males. Sex does not affect severity. In most cases, the course is mild to moderate and tends to resolve spontaneously without intervention.
• The lesions found in infantile acne include comedones, often associated with inflammatory papules, pustules, nodules, and cysts. It may sometimes result in scarring.
• Acne vulgaris initially presenting in prepubertal children aged 1 to 7 is very rare. It is a possible indication of higher levels of androgens than is expected for the age of the child (i.e., a hyperandrogenic state), resulting in additional signs of precocious puberty and/or virilization. If present, further diagnostic workup and referral and consultation with a pediatric endocrinologist are warranted.
• Infantile acne is more common in males. Hormone abnormalities in children with acne are associated with congenital adrenal hyperplasia, Cushing syndrome, 21-hydroxylase deficiency, precocious puberty, androgen-secreting tumors, medications, and premature adrenarche.

Question 23

A 13-year-old boy presents with a one-month history of firm edema of the neck. Physical examination shows a woody induration of the skin with overlying erythema. The diagnosis of scleredema of Buschke type 1 is considered. Which of the following findings increases the likelihood of the diagnosis?

1. A two-year history of diabetes type 1
2. A one-month history of acute post-streptococcal glomerulonephritis
3. History of acute leukemia
4. Obesity

Answer 23

2 - A one-month history of acute post-streptococcal glomerulonephritis Explanations:

• The diagnosis of scleredema is based on clinical findings. Scleredema type 1 is commonly observed in children and young adults. Scleredema type 1 usually follows an acute febrile infection. The most common infection is streptococcal pharyngitis.
• Post-streptococcal disorders usually occur 2 to 3 weeks following infection with group A streptococcus. They include acute rheumatic fever and acute glomerulonephritis. The history of acute glomerulonephritis confirms the streptococcal infection.
• Diabetes type 2 and hematological abnormalities are associated with scleredema type 2 and 3.

Question 24

A 75-year-old gentleman presents to the clinic with recently diagnosed polycythemia vera. Six months prior to his diagnosis, he reported experiencing burning pain in the bilateral lower extremities relieved only by dunking them in cold water. Which of the following is the most likely underlying pathology?

1. Erythromelalgia
2. Diabetic neuropathy
3. Peripheral arterial disease
4. Cellulitis

Answer 24

1 - Erythromelalgia

• Erythromelalgia is a rarely occurring disease entity characterized by a triad of erythema, warmth, and recurrent burning pain, most notably affecting the extremities.
• Erythromelalgia can be classified as being either primary or secondary.
• Patients will frequently present with reports of red, hot, swollen acral sites including the hands, feet, and rarely the face. The pain is often described as a burning, searing pain that is triggered by exercise, warm climates, and wearing tight-fitting shoes amongst other inciting agents. Often times, erythromelalgia can be the presenting manifestation of secondary causes.
• While cellulitis often presents with erythema, warmth and burning pain, this presentation more closely represents erythromelalgia. Erythromelalgia is a rarely occurring disease entity characterized by a triad of erythema, warmth, and recurrent burning pain most notably affecting the extremities. Erythromelalgia can be classified as being either primary or secondary.

Question 25

A 50-year-old Iranian male presents with ulcers of the mouth and penis for the past three months. They last for a week or two and then resolve. He also reports recurring painful nodules on his lower legs. 0.3 ml of sterile saline is injected under the skin to perform a pathergy test with the working diagnosis of Behcet disease. Which reaction would be expected?

1. Necrotic ulcer in 48 hours
2. Urticaria in 10 minutes
3. 15 mm of induration with erythema
4. 2 to 3 mm papules in 2 to 3 days

Answer 25

4 - 2 to 3 mm papules in 2 to 3 days

• Behcet disease often presents in patients from the Middle East, Far East, and the Mediterranean.
• Patients have recurrent oral ulcers and at least two of the following symptoms: genital ulcers, eye lesions, skin lesions such as erythema nodosum, or a positive pathergy test.
• The pathergy test is a reaction of nonspecific skin inflammation occurring two to three days after a scratch or injection of sterile saline.
• While patients are at increased risk for deep venous thrombosis, most have a normal lifespan.

Question 26

A 65-year-old man on total parenteral nutrition develops an erythematous rash around his mouth and nose. On examination, he has red eyes and increased tearing consistent with conjunctivitis. Neurological examination shows ataxia and hypotonia. He is lethargic and depressed. Which of the following tests will confirm the nutrient deficiency?

1. Serum biotin
2. Serum propionic acid
3. Urine biotin
4. Urinary 3-hydroxyisovaleric acid

Answer 26

4 - Urinary 3-hydroxyisovaleric acid

• The urinary excretion of 3-hydroxyisovaleric acid is a sensitive and early indicator of biotin status.
• The activity of propionyl-CoA carboxylase in lymphocytes is another marker for determining biotin status.
• Serum biotin levels are not reliable indicators of marginal biotin deficiency. Evidence shows that serum biotin concentration does not decrease in biotin deficiency patients who are receiving biotin-free total parenteral nutrition.
• Biotinidase deficiency confirmation is done by DNA analysis, either allele-targeted methods or full-gene sequencing.

Question 27

A patient presents with severe acne with interconnecting abscesses and irregular scars. The comedones occur in groups of 2 or 3 and the cysts are foul-smelling with seropurulent material that returns after drainage. The nodules are found on the chest, face, shoulders, back, and buttocks. Which of the following is the most likely cause of the patient’s condition?

1. Acne fulminans
2. Acne vulgaris
3. Acneiform eruption
4. Acne conglobata

Answer 27

4 - Acne conglobata

• Acne conglobata is a rare form of acne characterized by burrowing and interconnecting abscesses and irregular scars causing pronounced disfigurement.
• The comedones occur in groups of 2 or 3, and cysts contain foul-smelling seropurulent material that returns after drainage.
• The nodules are most commonly found on the face, chest, shoulders, back, buttocks, upper arms, and thighs.
• Acne conglobata may develop as a result of a sudden deterioration of existing papular or pustular acne, or it may occur as the recrudescence of acne quiescent for many years.

Question 28

A 32-year-old female patient presents with a chief complaint of a rapidly progressing ulcerative lesion on her lower extremity. You notice the ulcer has a purulent base with an undermined border. You suspect the patient may have pyoderma gangrenosum. What percentage of patients with pyoderma gangrenosum have underlying inflammatory bowel disease?

1. 5%
2. 25%
3. 50%
4. 75%

Answer 28

3 - 50%

• The presence of pyoderma gangrenosum should prompt physicians to consider a diagnosis of inflammatory bowel disease (IBD) as well.
• The lesions of pyoderma gangrenosum typically start as a tender papulopustule which then undergoes necrosis to form an ulcerated area. The fully developed lesion is an ulcer with a sterile, purulent base with an undermined, gun-metal colored border.
• The most common location of pyoderma gangrenosum in adults is the lower extremities.
• The disease course of pyoderma gangrenosum has not been found to parallel the disease course of Crohn disease or ulcerative colitis.

Question 29

A 17-year-old woman presents with painful lesions on bilateral ankles made worse by long periods of standing, tight, narrow shoes, and running. The physical examination is remarkable for numerous 0.5-1 centimeter skin-colored papules protruding from her bilateral lateral heels while she stands, which disappears after she is seated. Which of the following is the most appropriate management of this condition?

1. Intralesional injections of betamethasone and bupivacaine
2. Topical corticosteroids
3. Topical imiquimod
4. Cryotherapy

Answer 29

1 - Intralesional injections of betamethasone and bupivacaine

• Piezogenic papules are typically benign and most often painless thus do not require treatment.
• Should lesions become painful conservative management, including behavioral modification, avoiding prolonged standing, weight loss, reducing foot trauma should be considered first.
• Subsequently, compression stockings, heel cups, and orthotics should be implemented. More invasive techniques should be reserved for refractory cases. Intralesional injections of betamethasone and bupivacaine have been reported with some promise in patients with Ehlers-Danlos syndrome.
• Lastly, surgical intervention, if the lesion is severely painful, may help.

Question 30

A 35-year-old female with type 2 diabetes mellitus presented to the clinic with hyperkeratotic papules and nodules on her lower extremities. Histopathology showed transdermal elimination of keratotic material. What would be the first-line therapy?

1. Surgical excision
2. Salicylic acid
3. Renal transplant
4. Carbon dioxide laser therapy

Answer 30

2 - Salicylic acid

• Keratolytics such as salicylic acid or urea are often used as first-line therapy for Kyrle disease due to the hyperkeratotic nature of the disease. Topical and oral retinoids have also been used with success. However, there are no well-designed randomized control trials studying treatment therapies in Kyrle disease and evidence is based on anecdotal reports and small case series.
• Surgical excision has been used in the treatment of severe, refractory Kyrle disease.
• Kyrle disease is commonly associated with end-stage renal disease, and about 10% of hemodialysis patients will develop Kyrle disease. Renal transplantation has lead to complete regression of skin lesions in this particular patient population.
• Carbon dioxide laser, electrocautery, cryotherapy, and PUVA are alternative treatment options for Kyrle disease, but they are more invasive and painful compared to keratolytics.