Abnormalities in wound healing US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Abnormalities in wound healing. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Abnormalities in wound healing US Medical PG Question 1: A 62-year-old woman is hospitalized for an open reduction of a fracture of her right femur following a motor vehicle accident 2 hours prior. She has had rheumatoid arthritis for 12 years. She was hospitalized 1 month ago for an exacerbation of rheumatoid arthritis. Since then, she has been taking a higher dose of prednisone to control the flare. Her other medications include calcium supplements, methotrexate, and etanercept. She has had appropriate nutrition over the years with regular follow-ups with her healthcare providers. Her vital signs are within normal limits. Cardiovascular examination shows no abnormalities. In order to reduce the risk of post-operative wound failure, which of the following is the most appropriate modification in this patient’s drug regimen?
- A. Replacing prednisone with hydrocortisone
- B. Applying topical vitamin C
- C. Adding zinc supplementation (Correct Answer)
- D. Discontinuing steroids before surgery
- E. Increasing prednisone dose initially and tapering rapidly after 3 days
Abnormalities in wound healing Explanation: ***Adding zinc supplementation***
- **Zinc** plays a crucial role in **collagen synthesis**, immune function, and **wound healing**, making supplementation beneficial for reducing post-operative wound failure, especially in patients with chronic inflammatory conditions or those on corticosteroids.
- Chronic inflammation from **rheumatoid arthritis** and long-term **corticosteroid use** can impair zinc absorption and lead to deficiency, which exacerbates wound healing issues.
*Replacing prednisone with hydrocortisone*
- Both **prednisone** and **hydrocortisone** are corticosteroids, and switching between them does not inherently reduce the risk of wound failure.
- While prednisone is converted to prednisolone in the liver, hydrocortisone is directly active; both have similar immunosuppressive and anti-inflammatory effects that can impair wound healing.
*Applying topical vitamin C*
- **Topical vitamin C** is primarily used for its antioxidant properties and role in collagen synthesis in the skin, but its systemic effect on deep surgical wound healing is limited.
- **Systemic vitamin C deficiency** can impair wound healing, but the patient's history of appropriate nutrition suggests this is less likely to be the primary issue.
*Discontinuing steroids before surgery*
- Abruptly discontinuing **prednisone**, especially in a patient on a higher dose for an **RA flare**, carries a high risk of causing an **adrenal crisis**, which is life-threatening.
- Steroids are typically continued at a stress-dose equivalent during surgery to prevent **adrenal insufficiency**, not discontinued.
*Increasing prednisone dose initially and tapering rapidly after 3 days*
- Increasing the **prednisone dose** pre-operatively could further suppress the immune system and impair wound healing, increasing the risk of infection and dehiscence.
- While a **stress-dose steroid** regimen is appropriate, the goal is to provide physiological replacement, not to significantly increase the dose beyond what is necessary to prevent adrenal crisis.
Abnormalities in wound healing US Medical PG Question 2: A 55-year-old African American female presents to her breast surgeon for a six-month follow-up visit after undergoing a modified radical mastectomy for invasive ductal carcinoma of the left breast. She reports that she feels well and her pain has been well controlled with ibuprofen. However, she is frustrated that her incisional scar is much larger than she expected. She denies any pain or pruritus associated with the scar. Her past medical history is notable for systemic lupus erythematosus and multiple dermatofibromas on her lower extremities. She has had no other surgeries. She currently takes hydroxychloroquine. On examination, a raised hyperpigmented rubbery scar is noted at the inferior border of the left breast. It appears to have extended beyond the boundaries of the initial incision. Left arm range of motion is limited due to pain at the incisional site. Abnormal deposition of which of the following molecules is most likely responsible for the appearance of this patient’s scar?
- A. Type III collagen
- B. Proteoglycan
- C. Elastin
- D. Type I collagen (Correct Answer)
- E. Type II collagen
Abnormalities in wound healing Explanation: ***Correct: Type I collagen***
- Keloids are characterized by an **overgrowth of dense, disorganized type I collagen fibers** that extend beyond the original wound boundaries. The patient's scar is described as a **"raised, hyperpigmented, rubbery scar" that "extended beyond the boundaries of the initial incision,"** which is characteristic of a keloid.
- Patients with **African American ethnicity**, a history of **dermatofibromas** (which can predispose to keloid formation), and a lack of pain or pruritus are all consistent with a keloid.
- Type I collagen comprises **over 80% of the collagen in mature keloid tissue** and accounts for the characteristic firm, raised appearance.
*Incorrect: Type III collagen*
- **Type III collagen** is prominent during the **initial proliferative phase of wound healing** and is later replaced by type I collagen in mature scars.
- While present early in wound healing, its excessive deposition is not the primary feature of a **mature keloid** that extends beyond the wound margins.
- Normal scars have a type I to type III collagen ratio of approximately 4:1, while keloids have a much higher ratio.
*Incorrect: Proteoglycan*
- **Proteoglycans**, such as decorin and biglycan, are components of the extracellular matrix that play a role in collagen fibril assembly and tissue hydration.
- Although proteoglycans are found in keloids, their **abnormal deposition** is secondary to the extensive collagen formation and not the primary structural molecule responsible for the bulk and characteristic appearance of the scar.
*Incorrect: Elastin*
- **Elastin** provides **elasticity and recoil** to tissues, such as skin, blood vessels, and ligaments.
- Keloids are characterized by **fibrosis and rigidity**, not increased elasticity, and abnormal elastin deposition is not the hallmark of their pathogenesis.
*Incorrect: Type II collagen*
- **Type II collagen** is primarily found in **hyaline cartilage** and vitreous humor, providing resistance to intermittent pressure.
- It is **not a significant component of skin or scar tissue**, making its abnormal deposition irrelevant to the pathogenesis of cutaneous keloids.
Abnormalities in wound healing US Medical PG Question 3: A 48-year-old man is brought to the emergency department with a stab wound to his chest. The wound is treated in the emergency room. Three months later he develops a firm 4 x 3 cm nodular mass with intact epithelium over the site of the chest wound. On local examination, the scar is firm, non-tender, and there is no erythema. The mass is excised and microscopic examination reveals fibroblasts with plentiful collagen. Which of the following processes is most likely related to the series of events mentioned above?
- A. Development of a fibrosarcoma
- B. Foreign body response from suturing
- C. Staphylococcal wound infection
- D. Poor wound healing from diabetes mellitus
- E. Keloid scar formation (Correct Answer)
Abnormalities in wound healing Explanation: ***Keloid scar formation***
- A **keloid** is a raised, firm, nodular scar that extends beyond the original wound boundaries and is characterized by excessive collagen deposition from **fibroblasts**.
- The delayed presentation (3 months), firm nature, absence of inflammation (no erythema, non-tender), and microscopic findings of fibroblasts with plentiful collagen are classic features of a keloid.
*Development of a fibrosarcoma*
- A fibrosarcoma is a **malignant tumor** of fibroblasts, which would typically present with more aggressive growth, often pain, and possibly ulceration, none of which are described.
- While composed of fibroblasts, fibrosarcomas exhibit **cellular atypia**, mitotic activity, and invasion, which are not mentioned in the microscopic description.
*Foreign body response from suturing*
- A foreign body response usually involves a **granulomatous inflammation** around foreign material, such as suture remnants.
- The microscopic description of "fibroblasts with plentiful collagen" without mention of inflammatory cells or foreign bodies makes this less likely.
*Staphylococcal wound infection*
- A **bacterial infection** would typically present with signs of acute inflammation such as erythema, warmth, pain, and possibly pus, shortly after the wound.
- The mass is described as non-tender with no erythema, and the 3-month delay makes an active infection less probable.
*Poor wound healing from diabetes mellitus*
- Poor wound healing in diabetes often manifests as **delayed closure**, chronic ulcers, and increased susceptibility to infection, rather than an overgrowth of fibrous tissue in the form of a nodular mass.
- While diabetes can affect wound healing, the specific description of a firm, nodular mass with excessive collagen points away from typical diabetic wound complications.
Abnormalities in wound healing US Medical PG Question 4: A 28-year-old woman and her husband are admitted to the office due to difficulties conceiving a child for the past year. Her menarche was at the age of 15 years, and her periods have been regular since then. Her medical history is positive for an abortion with curettage 5 years ago. A spermogram on the partner is performed, and it shows motile sperm cells. An ultrasound is performed on the patient and it is unremarkable. The laboratory results show that the FSH, LH, TSH, and prolactin levels are within normal ranges. A hysteroscopy is additionally performed and multiple adhesions are found in the uterus (refer to the image). Which of the following is the most likely composition of the scar tissue present in the uterus?
- A. Type 3 collagen
- B. Type 4 collagen
- C. Type 2 collagen
- D. Type 1 collagen (Correct Answer)
- E. Elastin
Abnormalities in wound healing Explanation: ***Type 1 collagen***
- This patient presents with **Asherman's syndrome**, characterized by intrauterine adhesions, often following uterine surgery like **curettage**. These adhesions are primarily composed of **Type 1 collagen**, which is the most abundant type of collagen in the human body and a major component of scar tissue.
- **Type 1 collagen** provides tensile strength and is crucial for wound healing and forming scar tissue in most connective tissues, including the uterus.
*Type 3 collagen*
- **Type 3 collagen** is found in distensible tissues like blood vessels, the uterus, and skin, and is important during the **early stages of wound healing**.
- While present in the uterus and initially involved in wound repair, **mature scar tissue** predominantly consists of **Type 1 collagen**.
*Type 4 collagen*
- **Type 4 collagen** is a major component of the **basal lamina**, a specialized extracellular matrix that underlies epithelial and endothelial cells.
- It does not form fibrillar structures and is not the primary component of robust scar tissue found in Asherman's syndrome.
*Type 2 collagen*
- **Type 2 collagen** is the main collagen type found in **hyaline cartilage** and elastic cartilage, providing resistance to pressure.
- It is not found in significant amounts in uterine tissue or scar tissue formed within the uterus.
*Elastin*
- **Elastin** is a protein that provides **elasticity** to tissues like blood vessels, skin, and lungs, allowing them to stretch and recoil.
- While present in the uterus for its contractile properties, it is not the primary constituent of **fibrotic scar tissue** forming adhesions.
Abnormalities in wound healing US Medical PG Question 5: A 35-year-old man is pulled out of a burning building. He is unconscious and severely injured. He is transported to the nearest emergency department. Upon arrival, he is stabilized and evaluated for burns and trauma. Approximately 40% of his body is covered in burns. The burned areas appear blackened and charred but the skin is mostly intact. It is noted that the patient has loss of pain sensation in the burnt areas with minimal blanching on palpation. The affected area is leathery when palpated. What category of burn did the patient most likely to suffer from?
- A. Superficial (1st degree)
- B. Full-thickness (3rd degree) (Correct Answer)
- C. Superficial-partial thickness (2nd degree)
- D. Deep-partial thickness (deep 2nd degree)
- E. Full-thickness with extension to underlying structures (4th degree)
Abnormalities in wound healing Explanation: ***Full-thickness (3rd degree)***
- The description of **blackened, charred appearance**, **loss of pain sensation**, **minimal blanching**, and **leathery texture** are classic signs of a **full-thickness (3rd-degree) burn**.
- **Full-thickness burns** destroy the entire dermis, including nerve endings, leading to a painless area.
- The leathery texture results from protein coagulation in the destroyed dermis.
*Superficial (1st degree)*
- This type of burn affects only the **epidermis**, causing redness, pain, and no blistering.
- The patient's presentation of charred skin and insensitivity to pain is inconsistent with a **superficial burn**.
*Superficial-partial thickness (2nd degree)*
- **Superficial partial-thickness burns** involve the epidermis and superficial dermis, characterized by painful blisters and redness.
- The absence of pain and presence of charred skin rule out this type of burn.
*Deep-partial thickness (deep 2nd degree)*
- **Deep partial-thickness burns** extend into the deep dermis and may have **decreased pain sensation** due to nerve damage.
- However, these burns typically appear **mottled red or white** rather than blackened and charred, and usually have some blanching response.
- The completely charred, blackened appearance with absent pain indicates full-thickness injury.
*Full-thickness with extension to underlying structures (4th degree)*
- A **4th-degree burn** extends beyond the skin into **muscle, bone, or tendons**, often with visible destruction of these structures.
- The affected area would typically be **very firm or hard** with exposed deeper tissues.
- While the burn is severe, the description focuses on skin characteristics without obvious involvement of deeper anatomical structures like muscle or bone.
Abnormalities in wound healing US Medical PG Question 6: A 56-year-old woman undergoes open reduction and internal fixation of the distal tibia 1 day after a fall. She has had rheumatoid arthritis for 12 years and diabetes mellitus for 2 years. Her medications over the past year have included metformin, prednisone, calcium supplements, and methotrexate. Prior to surgery, insulin was added to her medications, and the dose of prednisone was increased. She has had appropriate nutrition over the years with regular follow-ups with her healthcare professional. Which of the following is the most appropriate supplement to prevent wound failure in this patient?
- A. Glutamine
- B. Zinc
- C. Vitamin A
- D. Arginine
- E. Vitamin C (Correct Answer)
Abnormalities in wound healing Explanation: ***Vitamin C***
- This patient is at high risk for **wound healing complications** due to her comorbidities (diabetes, rheumatoid arthritis) and medications (prednisone, methotrexate). **Vitamin C** (ascorbic acid) is essential for **collagen synthesis** and cross-linking, which is crucial for wound strength and tissue repair.
- While other options play a role in wound healing, Vitamin C is particularly important in patients with **impaired healing** due to chronic inflammation, corticosteroid use, and metabolic disorders, as it counteracts their negative effects on collagen formation.
*Glutamine*
- **Glutamine** is an important fuel for rapidly dividing cells, including immune cells and fibroblasts, and can be beneficial in catabolic states.
- However, its role in directly counteracting the specific challenges of this patient's wound healing (corticosteroid use, diabetes, rheumatoid arthritis) is **less direct** compared to Vitamin C's role in collagen synthesis.
*Zinc*
- **Zinc** is a cofactor for numerous enzymes involved in cell proliferation, immune function, and collagen synthesis.
- While important, zinc deficiency is not explicitly indicated, and its role as a primary intervention to prevent wound failure in a patient with **prednisone-induced healing impairment** is secondary to vitamin C.
*Vitamin A*
- **Vitamin A** can help reverse the negative effects of **corticosteroids** on wound healing by promoting epithelialization and collagen synthesis.
- While relevant due to prednisone use, its overall importance in **collagen formation** and direct wound strength is not as profound or broad as Vitamin C.
*Arginine*
- **Arginine** is a precursor for nitric oxide, which improves blood flow to wounds, and is involved in collagen formation and immune function.
- Although beneficial for wound healing, particularly in critically ill patients, it is **not the most appropriate single supplement** for addressing the specific collagen synthesis impairment seen in this patient's context of corticosteroid use and chronic disease.
Abnormalities in wound healing US Medical PG Question 7: A 51-year-old woman presents to the dermatologist with concern for a new skin lesion (Image A). You note two similar lesions on her back. Which of the following is a true statement about these lesions?
- A. They must be followed closely for concern of malignancy.
- B. They will likely regress spontaneously.
- C. They may be associated with von Hippel-Lindau disease.
- D. They will likely grow rapidly.
- E. They will likely increase in number over time. (Correct Answer)
Abnormalities in wound healing Explanation: ***They will likely increase in number over time.***
- The image likely displays **cherry angiomas**, which are common benign vascular lesions that typically increase in number with age.
- While individual lesions may remain stable, their overall prevalence on the skin tends to rise as a person ages, especially after the age of 30.
*They must be followed closely for concern of malignancy.*
- **Cherry angiomas** are **benign vascular proliferations** and do not carry a risk of malignant transformation.
- They are typically diagnosed clinically and do not require ongoing surveillance for malignancy.
*They will likely regress spontaneously.*
- **Cherry angiomas** are **permanent lesions** and do not typically regress spontaneously.
- Once they appear, they usually persist and often grow slightly in size over time.
*They may be associated with von Hippel-Lindau disease.*
- **Von Hippel-Lindau (VHL) disease** is associated with **hemangioblastomas** (in the CNS and retina), **pheochromocytomas**, and **renal cell carcinoma**, but not typically cherry angiomas.
- The characteristic skin lesions in VHL are often **cutaneous cavernous hemangiomas** or **capillary malformations**, not the common cherry angioma.
*They will likely grow rapidly.*
- While cherry angiomas can slowly increase in size over many years, they do **not typically grow rapidly**.
- Rapid growth of a cutaneous lesion would be a more concerning feature for other conditions, such as **malignant melanoma** or a **rapidly growing cyst**, not cherry angiomas.
Abnormalities in wound healing US Medical PG Question 8: A 23-year-old woman comes to the physician for evaluation of two masses on her right auricle for several months. The masses appeared a few weeks after she had her ear pierced and have increased in size since then. A photograph of her right ear is shown. Which of the following is the most likely cause of these findings?
- A. Implantation of epidermis into the dermis
- B. Malignant transformation of keratinocytes
- C. Increased production of hyalinized collagen (Correct Answer)
- D. Excess formation of organized extracellular matrix
- E. Infection with human papilloma virus
Abnormalities in wound healing Explanation: ***Increased production of hyalinized collagen***
- The image shows **keloids**, which are characterized by the overgrowth of **dense, hyalinized collagen** that extends beyond the original wound boundaries.
- Keloids often develop after skin trauma like ear piercing, and they tend to grow and persist, consistent with the patient's presentation.
*Implantation of epidermis into the dermis*
- This process typically leads to the formation of an **epidermoid cyst** or **inclusion cyst**, which is usually a smooth, mobile, subcutaneous nodule filled with keratinous debris.
- While it can occur after trauma like piercing, the resulting lesion does not typically have the exophytic, firm, and irregular appearance of the masses shown.
*Malignant transformation of keratinocytes*
- Malignant transformation of keratinocytes would suggest a skin cancer like **squamous cell carcinoma**, which can appear as an ulcerated, nodular, or scaly lesion.
- These lesions are typically not a result of ear piercing and do not present as uniform, firm, shiny masses extending beyond the wound boundary as seen in the image.
*Excess formation of organized extracellular matrix*
- While keloids do involve excess extracellular matrix (ECM) production, the term "organized extracellular matrix" is too broad and does not specifically describe the characteristic pathological feature seen in keloids.
- The key specific feature of keloids is the overabundance of **thick, hyalinized collagen bundles**, which is a more precise histological description than generally "organized extracellular matrix."
*Infection with human papilloma virus*
- **Human Papillomavirus (HPV)** causes **warts**, which are typically rough, papillomatous, and often have a "cauliflower-like" appearance.
- Warts are not typically smooth, firm, and well-demarcated masses, nor do they usually grow to this size on the ear after a piercing, and their histology involves epidermal hyperplasia rather than collagen overgrowth.
Abnormalities in wound healing US Medical PG Question 9: A 31-year-old Israeli male with a history of heavy smoking presents to your office with painful ulcerations on his hands and feet. Upon examination, he is found to have hypersensitivity to intradermally injected tobacco extract. Which of the following processes is most likely responsible for his condition?
- A. Eosinophil-rich granulomatous inflammation
- B. Segmental vasculitis of small and medium-sized arteries (Correct Answer)
- C. Increased endothelial permeability
- D. Necrotizing inflammation involving renal arteries
- E. Concentric thickening of the arteriolar wall
Abnormalities in wound healing Explanation: ***Segmental vasculitis of small and medium-sized arteries***
- This presentation is highly characteristic of **Buerger's disease (thromboangiitis obliterans)**, which is a **segmental, inflammatory vasculitis** primarily affecting small and medium-sized arteries and veins of the hands and feet.
- Key features include **painful ulcerations of the hands and feet**, a strong association with **heavy smoking**, and often occurs in young to middle-aged adult males, with a higher prevalence in certain populations (e.g., of Israeli or Asian descent).
*Eosinophil-rich granulomatous inflammation*
- This type of inflammation is characteristic of conditions like **Churg-Strauss syndrome (eosinophilic granulomatosis with polyangiitis)**.
- Churg-Strauss syndrome typically involves asthma, allergic rhinitis, and eosinophilia, with vasculitis of small to medium vessels, not primarily affecting the distal extremities in this manner or having such a strong tobacco link.
*Increased endothelial permeability*
- While increased endothelial permeability is a feature of general inflammation and can contribute to edema, it is not the primary underlying pathological process causing the **segmental occlusive vasculitis** seen in Buerger's disease.
- This describes a general vascular response rather than a specific disease pathology.
*Necrotizing inflammation involving renal arteries*
- **Necrotizing inflammation of renal arteries** is characteristic of conditions like **polyarteritis nodosa (PAN)** or other systemic vasculitides that can affect renal vessels.
- These conditions typically present with systemic symptoms, hypertension, and renal dysfunction, which are not described in this patient.
*Concentric thickening of the arteriolar wall*
- **Concentric thickening of arteriolar walls** is a hallmark of **hypertensive arteriolosclerosis** or other forms of systemic hypertension.
- This finding would explain chronic end-organ damage from hypertension but does not account for the acute, painful ulcerations in the extremities associated with heavy smoking.
Abnormalities in wound healing US Medical PG Question 10: A 62-year-old man comes to the physician because of a swollen and painful right knee for the last 3 days. He has no history of joint disease. His vital signs are within normal limits. Examination shows erythema and swelling of the right knee, with limited range of motion due to pain. Arthrocentesis of the right knee joint yields 7 mL of cloudy fluid with a leukocyte count of 29,000/mm3 (97% segmented neutrophils). Compensated polarized light microscopy of the aspirate is shown. Which of the following is the most likely underlying mechanism of this patient's knee pain?
- A. Immune complex-mediated cartilage destruction
- B. Calcium pyrophosphate deposition (Correct Answer)
- C. Bacterial infection of the joint
- D. Mechanical stress and trauma
- E. Monosodium urate deposition
Abnormalities in wound healing Explanation: ***Calcium pyrophosphate deposition***
- The **cloudy fluid** with a leukocyte count of **29,000/mm³** predominantly composed of **segmented neutrophils** indicates acute inflammation, characteristic of **pseudogout** (calcium pyrophosphate dihydrate crystal deposition disease).
- **Compensated polarized light microscopy** would reveal **weakly positive birefringent rhomboid-shaped crystals**, confirming CPPD deposition.
- The **age** of the patient (62 years), **acute monoarticular involvement of the knee**, and sudden onset support a diagnosis of **pseudogout**.
*Immune complex-mediated cartilage destruction*
- This mechanism is characteristic of **rheumatoid arthritis** or **systemic lupus erythematosus**, which present with **chronic polyarticular involvement** and systemic features.
- The acute monoarticular presentation and synovial fluid findings are inconsistent with an immune complex-mediated process.
*Bacterial infection of the joint*
- Septic arthritis typically presents with **synovial fluid WBC counts >50,000/mm³** (often >100,000), though some overlap exists.
- The **absence of fever** and presence of **crystal findings on polarized microscopy** distinguish pseudogout from bacterial infection.
- Septic arthritis would not show crystals on microscopy and would require immediate Gram stain and culture.
*Mechanical stress and trauma*
- While mechanical injury can cause joint effusion, the **high neutrophil count** and **acute inflammatory findings** indicate a crystal-induced or infectious arthropathy rather than traumatic injury.
- There is no history of **trauma** reported, and traumatic effusions typically have lower WBC counts with predominantly red blood cells.
*Monosodium urate deposition*
- This indicates **gout**, which presents with **strongly negative birefringent needle-shaped crystals** on polarized microscopy (not the weakly positive birefringent rhomboid crystals of pseudogout).
- Gout more commonly affects the **first metatarsophalangeal joint** and typically occurs in younger patients with hyperuricemia risk factors.
- The patient's age and knee involvement are more consistent with **pseudogout**.
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