Welcome to your Skin Tumours & Dermatological Pharmacotherapy Arena
1.
A patient applies a potent topical corticosteroid under an occlusive dressing over a large inflamed area for an extended period. Which factor most directly increases the risk of systemic glucocorticoid effects in this situation?
2.
A 28-year-old patient with atopic dermatitis has recurrent facial lesions. Prolonged potent corticosteroid use is being avoided because of concern about cutaneous atrophy. A topical agent is prescribed that reduces cytokine production by suppressing calcineurin-dependent T-cell activation. Which drug was selected?
3.
A 73-year-old man with extensive sun-damaged skin has a firm crusted lesion on the ear. Histology shows invasive atypical keratinocytes with areas of eosinophilic material arranged concentrically within tumor nests. What process accounts for this histological appearance?
4.
A 24-year-old woman has a small blue-black papule that has remained unchanged for years. Histology demonstrates pigmented melanocytes located relatively deep in the dermis. Which optical consequence best explains the clinical color?
5.
A woman with severe psoriasis is prescribed a drug that reduces epidermal proliferation and immune-mediated inflammation. During follow-up, the physician monitors for hepatotoxicity and bone marrow suppression. Which medication is most likely being used?
6.
A 35-year-old woman has persistent facial hyperpigmentation and has been applying a skin-lightening preparation for a prolonged period without supervision. She later develops paradoxical blue-black pigmentation in the treated areas. Which drug is the most likely cause?
7.
A 70-year-old farmer has a persistent scaly plaque on the forearm. Biopsy shows marked atypia involving the full epidermal thickness. At one focus, atypical keratinocytes extend through the basement membrane into the superficial dermis. Which interpretation is most appropriate?
8.
A 64-year-old man develops a progressively enlarging ulcerated lesion within a long-standing burn scar on his leg. The lesion is firm at its base and biopsy confirms a keratinocyte malignancy. Which factor most likely contributed to its development?
9.
A patient with thick, scaly psoriatic plaques is given an additional topical preparation to remove excess keratin and improve penetration of other medication. Which mechanism best describes the action of the added drug?
10.
A 69-year-old man has an ulcerated lesion on the nose. Histology is required because the clinical distinction between two keratinocyte carcinomas is uncertain. Which paired finding would most strongly support basal cell carcinoma rather than squamous cell carcinoma?
11.
A patient with extensive vitiligo is considered for a treatment that deliberately removes remaining normal pigment to produce a more uniform skin color. The physician explains that the effect may be permanent because the drug damages melanocytes. Which agent is being considered?
12.
Histological examination of a melanoma shows that atypical melanocytes are no longer confined mainly to lateral epidermal spread but have formed an expanding invasive component within the dermis. Which change has occurred?
13.
A 46-year-old woman presents with a changing pigmented lesion on the lower leg. Histology shows atypical melanocytes present singly and in irregular nests, with some abnormal cells extending upward through the epidermis. Which morphological process does this represent?
14.
A 67-year-old woman has two facial lesions. One is a firm hyperkeratotic nodule with an ulcerated surface; the other is a slowly enlarging translucent papule with fine surface vessels and a raised edge. Which feature of the second lesion best predicts its biological behavior?
15.
A 19-year-old woman with inflammatory acne has been using topical clindamycin alone for several months. Her lesions initially improved but have started recurring. The physician adds another topical agent mainly to reduce the emergence of resistant Cutibacterium acnes. Which agent is most appropriate?
16.
A 63-year-old woman has a persistent rough lesion on a sun-exposed forearm. Several months later it becomes thicker, firm and ulcerated. Which sequence best explains the pathological progression suggested by this change?
17.
A 24-year-old woman has acne associated with residual dark macules after inflammatory lesions heal. Her physician selects a topical drug that has both antimicrobial activity against acne-associated bacteria and an inhibitory effect on abnormal pigmentation. Which drug best fits this profile?
18.
Histological examination of a facial tumor shows nests of small basaloid cells extending into the dermis. The outermost nuclei of the nests are arranged in an orderly row, with cleft-like spaces between tumor and stroma. Which diagnosis best fits these findings?
19.
Two patients require topical corticosteroids. One has mild facial atopic dermatitis, while the other has a thick hyperkeratotic psoriatic plaque on the sole. Why may the second lesion require a more potent preparation?
20.
A 35-year-old man has multiple clinically atypical melanocytic lesions but no evidence of melanoma on current examination. What is the most important implication of this finding?
21.
A 46-year-old man with chronic plaque psoriasis is prescribed a topical drug that binds a nuclear receptor in keratinocytes, reduces excessive proliferation and promotes more normal cellular differentiation. Which drug best fits this mechanism?
22.
A 28-year-old woman has several atypical pigmented lesions. One lesion is asymmetric, has poorly defined borders and contains different shades of brown. Biopsy shows irregular melanocytic nests, architectural disorder at the dermoepidermal junction and cytological atypia. Which lesion is most consistent with these findings?
23.
A school-aged child with head lice is being treated along with affected household contacts. The physician explains that another antiparasitic drug acts by increasing chloride entry into parasite nerve and muscle cells, leading to paralysis. Which agent has this mechanism?
24.
A family is treated for scabies after several members develop nocturnal pruritus. One patient reports mild burning and stinging after applying the prescribed topical medication but has no systemic symptoms. Which interpretation is most appropriate?
25.
A patient born with a large melanocytic lesion asks why regular clinical assessment may be important. Which feature of this lesion gives it greater clinical significance than an ordinary small acquired nevus?
26.
A 68-year-old man with multiple superficial actinic keratoses applies a topical medication. Several days later, the treated areas become erythematous and eroded as abnormal proliferating epidermal cells are damaged. The drug acts by reducing thymidine availability for DNA synthesis. Which agent is most likely responsible?
27.
A 62-year-old woman has a persistent red scaly plaque that has gradually enlarged over several months. Histology shows severe keratinocyte atypia throughout the epidermis, while the dermis remains free of tumor. Which structural event would indicate progression to an invasive malignancy?
28.
A 22-year-old man with inflammatory acne is prescribed doxycycline. He develops marked sunburn after brief outdoor exposure. Which pharmacological property of his treatment best explains this complication?
29.
A patient treated for scabies continues to experience itching shortly after otherwise appropriate therapy. Examination shows no new burrows or active lesions. Which explanation best accounts for the persistent symptom?
30.
A 52-year-old man is found to have a suspicious pigmented lesion on his back. Another patient has a suspicious lesion beneath a toenail. Which statement best reflects the distribution of melanoma?
31.
A 48-year-old man notices that a pigmented lesion on his back has become increasingly asymmetric and now contains black, brown and pale areas. Biopsy shows atypical melanocytes spreading laterally within the epidermis before significant deep invasion. Which growth pattern is being demonstrated?
32.
A patient with vitiligo receives a photosensitizing medication followed by controlled ultraviolet A exposure to encourage repigmentation. Which adverse effect is most directly related to the pharmacological basis of this treatment?
33.
A 16-year-old boy has a stable pigmented nevus surrounded by a symmetric depigmented ring. There is no ulceration or irregular growth. Which process best explains the pale surrounding skin?
34.
A 32-year-old man with androgenetic alopecia is prescribed a drug that slows progressive follicular miniaturization. The benefit results from reducing formation of a potent androgen metabolite within target tissues. Which mechanism is responsible?
35.
A 30-year-old woman with psoriasis is considering pregnancy. One proposed systemic treatment regulates epidermal differentiation but is avoided because of marked fetal toxicity. Which drug should raise the greatest concern?
36.
A patient with severe psoriasis improves rapidly after starting systemic immunosuppressive therapy. At follow-up, his blood pressure has increased and renal function has deteriorated. Which drug most likely produced this pattern?
37.
A 63-year-old man has several superficial actinic keratoses. A topical drug is selected that activates innate immune cells and promotes local cytokine production rather than directly inhibiting DNA synthesis. Which mechanism best accounts for its therapeutic effect?
38.
A child has a rapidly noticed solitary pink-red papule. Because of its clinical appearance, melanoma is considered, but histological assessment supports a benign melanocytic lesion that can closely mimic melanoma microscopically. Which type of nevus is most likely?
39.
A 58-year-old patient has a pigmented lesion with irregular color and shape. Dermoscopy increases clinical suspicion but cannot establish whether the lesion is a dysplastic nevus or melanoma. Which next diagnostic principle is most appropriate?
40.
A 59-year-old renal transplant recipient develops a new indurated skin lesion on a chronically sun-exposed forearm. Compared with an immunocompetent person, which mechanism most directly contributes to his increased risk of a keratinocyte carcinoma?
