P01.02 Skin and Subcutaneous Tissue (Part 2) PDF

PCC SOM 2026 SURGERY 2 P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) Treatment: based on Hurley staging with topical and...

PCC SOM 2026 SURGERY 2 P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) Treatment: based on Hurley staging with topical and systemic antibiotics (typically clindamycin) being used SURGERY LECTURE for stage I and II disease, while radical excision, laser LECTURER: Dr. Abraham Cinio treatment, and biologic agents are reserved for more DATE: August 8, 21, 2024 advanced stage II and III disease. Surgery: wide surgical debridement TOPIC HURLEY CLASSIFICATION OF HIDRADENITIS SUPPURATIVA Inflammatory Condition Stage I: Abscess formation, Skin Pigmentation which can be single or Collagen Types Supportive Care multiple, without sinus tracts and cicatrization (scar formation at the site of wound healing) INFLAMMATORY CONDITIONS Inflammatory conditions affecting the skin may be infected and clinically may be confused with a simple or complicated skin infections Stage II: Recurrent abscesses CASE 1: A female patient who developed painful subcutaneous with tract formation and nodules in the axilla. History revealed the usual hair clipping or cicatrization, single or shaving then appearance of the nodules multiple, widely separated Further history revealed progression of the lesions. symptoms and this time with the presence of ulceration and abscess formation. The patient smokes and intakes alcohol moderate, and has poor hygiene. - Abscess Stage III: Diffuse or near- - Ulceration diffuse involvement, or - Exudate from draining sinus multiple interconnected - Atrophic and hypertrophic scars tracts and abscesses across Diagnosis: Hidradenitis suppurativa the entire area EPIDERMAL NECROLYSIS A rare mucocutaneous disorder characterized by HIDRADENITIS SUPPURATIVA cutaneous destruction at the dermoepidermal Also known as acne inversa junction Can occur anywhere in the milk line Involves mucosal surfaces, oropharynx and can cause Most commonly found in the axilla and inguinal area GI bleeding, malabsorption and affect the eyes and for females genitalia Differential diagnosis: simple folliculitis Cell-mediated cytotoxicity targeted at keratinocytes Characterized by tender, deep nodules that can and the cytokine-induced expression of death expand, coalesce, spontaneously drain, and form receptors like Fas and its ligand Fas-L persistent sinus tracts in some cases leading to Management: Early withdrawal of the offending drug significant scarring and hyperkeratosis. is suggested Presentation is most commonly classified by the Supportive care is done while monitoring hydration Hurley classification (+) Nikolsky sign - Tangential skin pressure- causes epidermis to detach from basal layer NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 1 | 20  PCC SOM 2026 SURGERY 2 - P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) Lateral pressure on the skin causes separation of the Burning pain on skin epidermis from the dermis Erythema, blisters/bullae of the oropharynx fever sore throat Drugs Causing SJS mnemonic: PCP LAPSE Phenytoin Carbamazepine Phenobarbital Lamotrigine Allopurinol Penicillin Sulfa drugs Differentials: staphylococcal scalded skin syndrome Erythromycin (SSSS), pemphigus vulgaris, and herpes B. Toxic Epidermal Necrolysis 10%-30% of the total body surface is affected Circulating autoantibodies directed against the keratinocytes Table: Drugs causing Stevens-Johnson syndrome and toxic epidermal necrolysis Case2 : A child with presence of macular lesions in the face and trunk. In history, there was an initiation of a new drug treatment within 8 weeks. The lesions are burning in characteristic and eventually progressed to bullae formation and fever. Eventually, patient then developed sore throat and difficulty in eating C. Erythema multiforme → Discontinue the drug used to allow recovery Was once considered as part of the clinical subgroup A. Steven-Johnson Syndrome (SJS) encompassing SJS and TEN, but is now thought to be a separate entity related to herpetic and Mycoplasma pneumoniae infections 105) Inhibition of division Treatment: wound debridement and antibiotics - cell division is inhibited/delayed A course of 3 to 7 days of amoxicillin/clavulanate is Chromosome aberrations typically used. Alternatives are doxycycline or - structure or number of chromosome altered clindamycin with ciprofloxacin Gene mutation Typically, in areas of aesthetic importance, the - DNA sequence of A, T.G,C bases altered wound is thoroughly irrigated and debrided and Cell Killing/cell death primarily closed with a short course of antibiotics and - cell stops dividing or functioning close follow-up to monitor for signs of infection. In areas that are less cosmetically sensitive and bites that look grossly contaminated or infected, the Reading Assignment: wounds are allowed to close secondarily. CLASSIFICATION OF TUMOR RADIOSENSITIVITY Classification of tumor radiosensitivity is based on histology and divided into radiosensitive and radioresistant tumors based on their response to conventionally fractionated radiotherapy. Radiosensitive tumors include: Lymphoma Myeloma Seminoma Radioresistant tumors include: Renal cell Melanoma Thyroid Colorectal Radioresistant tumors require stereotactic body radiation therapy (SBRT) for durable control. Bite wound Management: 1. Flush with saline (irrigation) 2. Vaccine (anti-tetanus) 3. Betadine BITE WOUNDS 4. Suture (if recommended) The most common location of bite wounds is the In these case patient is admissible (usually under hand anesthesia (general)) NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 10 | 20  PCC SOM 2026 SURGERY 2 P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) Topical antimicrobials and non adherent dressings are used for partial-thickness wounds with surgical debridement and reconstruction if needed for full thickness injuries. Liposuction and saline dilution have been used in cases were injury to deeper structures was suspected. Prophylactic use of antibiotics is generally avoided. Hydrofluoric acid: behaves like an alkali because of its corrosiveness Treatment: Giving tetanus prophylaxis also depend on the size of Topical or locally the wound, location, and the manner which the skin injected calcium damage was wired gluconate ➔ Bind fluorine ions CHEMICAL INJURIES Topical calcium carbonate gel, quaternary ammonium compounds ➔ Detoxify fluoride ions Intra-arterial calcium gluconate ➔ Pain relief ➔ Preserve arteries from necrosis Extravasation Injury Coagulation necrosis (Acid) Often a result of unchecked IV lines - Eschar Commonly seen in the hospital - Irrigation: 30 minutes Injection site reactions from doxorubicin or calcium Liquefaction necrosis (Alkaline) carbonate - Fat saponification Extravasation is estimated to occur in 0.1% to 0.7% of - Irrigation: 2 hours all cytotoxic drug administrations. Like other chemical Tissue necrosis burns, extravasation injuries depend on properties of Uncontrolled pain the offending agent, time of exposure,concentration, Deep-tissue damage and volume of drug delivered to the tissues - Alkaline substances deal more damage than acid Management: substances - Limb elevation ** Common examples of agents that often cause alkaline - Saline infiltration chemical burns are sodium hydroxide (drain decloggers and - Aspiration by liposuction paint removers) and calcium hydroxide (cement). - Topical antimicrobial therapy Doxorubicin – most commonly associated substance, Treatment for acidic or alkaline chemical burns is first and an anti-cancer foremost centered around dilution of the offending agent, Calcium carbonate typically using distilled water or saline for 30 minutes for Impeded thermoregulatory mechanisms acidic burns and 2 hours for alkaline injuries. Attempting to - Vasoconstriction neutralize the offending agent is typically discouraged, as it - Pressure does not offer an advantage over dilution and the - Inflammation neutralization reaction could be exothermic, increasing the amount of tissue damage. NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 11 | 20  PCC SOM 2026 SURGERY 2 P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) It is best to avoid cold or warm compression because the impaired temperature regulation of the damaged tissue may lead to thermal injury. PRESSURE INJURIES Common cause of surgical referral from critically ill patients Excess pressure results in occlusion of capillary flow, causing ischemic injury and extravasation of fluid, cells, and protein The average perfusion pressure of the microcirculation is about 30 mmHg - Pressures greater than this can cause local tissue ischemia Tissues with a higher metabolic demand are typically susceptible to insult, tissue hypoperfusion - Muscles are prone to ischemia due to hypermetabolism Localized area of tissue destruction that develops when soft tissue is compressed between a bony prominence The most common areas affected are the bony prominence - Ischial tuberosities - The most common area affected (28%) - Trochanter/ Greater Trochanter - 19% - Sacrum - 17% - Heel - 9% Tissue pressure can measure up to 30 mmHg in the ischial region during sitting Tissue pressure can reach 150 mmHg over the sacrum while lying supine Negative pressure wound therapy (NPWT) - Draw wound edges together - Remove edema and infectious material - Promote perfusion and granulation tissue Pressure Sores Grading STAGE 1 - non-blanching erythema over intact skin STAGE 2 – partial thickness injury with blistering or exposed dermis STAGE 3 – full thickness injury extending down to but not including fascia and without undermining of adjacent tissue STAGE 4 – full thickness skin injury with destruction and necrosis of muscle, bone, tendon or joint capsule NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 12 | 20  PCC SOM 2026 SURGERY 2 P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) - Reduction of wound area Used for: traumatic injuries, surgical wounds, pressure ulcers, diabetic foot ulcers, and venous stasis ulcers Has been evolved to include automated instillation with dwell time Management: Prevention is the key Avoidance of prolonged pressure at risk areas Turn/reposition the patient every 2 hours (why? because it takes 2 hours for ischemic change to happen) Order early mobilization Provide prophylactic silicon dressings Specialized beds for prevention of pressure ulcers Patient should be optimally nutritionalized and surgically debrided as appropriate Stage III or IV pressure ulcers is not necessarily an This is an abdominal wound indication for surgery, and fevers in a patient with This could be a postoperative patient who had chronic pressure ulcers are often from a urinary or surgical site infection pulmonary source Stage 2 and 3 ulcers may be left to heal secondarily after debridement. Negative Pressure Wound Therapy (NPWT) This may be done on any wounds as long as the surface materials used permits Example: Wounds in the extremities - This device may be used and may be effective in A patient with a chronic non-healing wound. optimizing or helping in the healing of wound in these The patient is diabetic areas, compared to wounds in the sacral area Purposes: - Draw wound edges together - Remove edema and infectious material - Promote perfusion and granulation tissue - Tissue stretch and compression - Angiogenesis - Cellular proliferation - Fibroblast migration - Increased production of wound healing proteins NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 13 | 20  PCC SOM 2026 SURGERY 2 P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) - Fluctuance for abscess formation - Purpura - Bullae - Lymphangitis or spread of the infection from a particular area to its lymph node basin Bullae Complicated skin infections include superficial cellulitis encompassing a large surface area - More than 75 sq. cm Deeper infections spreading below the dermis Necrotizing soft tissue infections (NSTIs) including necrotizing fasciitis can include rapid extensive Types of Gangrene morbidity and mortality Dry Gangrene Wet Gangrene Shrinked, wrinkled, Swallow, edematous mummified Bad odor, purulent No odor ,, no discharge discharge, Line of demarcation No line of....... Line of separation Tissue above shows, Tissue above normal and edema , redness, healthy hemorrhagic bullae skip areas Crepitus may be present. This started as a pimple-like infection in the perineum The patient self-medicated and punctured the pustule The patient then came to the ER, complaining of perineal. Scrotal, and inguinal pain The diagnosis is Fournier’s gangrene (a type of Necrotizing Fasciitis) - The five fascial planes that can be affected are: Colles’ fascia, dartos fascia, Buck’s fascia, Scarpa’s fascia, and Camper’s fascia. Patients with skin complaints, we look for in the HX and PE: - Trauma (including insect bites) - Comorbidities like Diabetes Mellitus - Cirrhosis (alcoholic) - Drug abuse - Comorbid (including immunodeficiency like HIV) - Examine the lesions, its extent - Presence of crepitus of gas forming bacteria NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 14 | 20  PCC SOM 2026 SURGERY 2 Necrotizing infections P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) NSTIs are based on anatomic sites Subcutaneous tissue, fascia, and muscle may be affected Necrotizing fasciitis can involve the fascia and the infection can quickly travel on the vascular planes. Types: Type I Type II Type III 3. Dermatofibroma -Polymicrobial ➔Monomicrobial -Vibrio vulnificus Benign cutaneous that appear most commonly on the -Most common - Beta-hemolytic infection lower extremities -Includes Gram(+) streptococci -Traumatized skin Pink to brown papules that dimple at the center cocci, gram (-) - Staphylococci in sea divers when the lesion is pinched rods, anaerobic (including -Rare Basal cell carcinoma may develop within a bacteria like MRSA—MRSA -Exposure to salt- dermatofibroma Clostridium contributes to a water and in perfringens and growing number beaches Clostridium of NSTIs) septicum ➔ May be associated with toxic shock syndrome In wound healing, the causative agent must be 4. Neurofibromatosis known, comorbidities of the patient, and nutrition Benign Made up of nerve elements balances These arise as fleshy and non-tender, sessile masses and pedunculated BENIGN TUMORS OF THE SKIN May arise sporadically or in association with type 1 neurofibromatosis 1. Lipoma The pain at the site of a previous neurofibroma may The most common sub-neoplasm indicate a malignant transformation There is no malignant potential These are associated with café au lait spots and lisch Painless, slow-growing mobile mass nodules Liposarcoma is a malignant fatty tumor that can - These nodules are melanocytic hamartoma mimic a lipoma - These are found on the surface of the iris and are - Often deep-seated clear to yellow to brown. - Rapidly growing The pain at the site of a previous neurofibroma may - Painful indicate a malignant transformation - Invasive - We do not excise everything - We only excise nodules that are symptomatic to rule out any malignant transformation 2. Skin Tags/Acrochordons Benign, pedunculated lesions Made up of epidermal keratinocytes surrounding a core 5. Epidermoid Cyst Cutaneous cysts are characterized by overgrowth of epidermis towards the center of the lesion, resulting in keratin accumulation Sebaceous cyst NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 15 | 20  PCC SOM 2026 SURGERY 2 P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) Plugged by pilosebaceous units SQUAMOUS CELL CARCINOMA These commonly affect adult men and women Seen as a dermal sub-q cyst with a single keratin plug 2nd most common skin cancer entombed at the skin surface Associated with UV exposure - Upper chest and back Invasive SCC is characterized by invasion through the Most common cutaneous cysts basement membrane into the dermis of the skin. It Characterized by mature epidermis complete with a usually arises from an actinic keratosis precursor, but granular layer de novo varieties do occur and are higher risk. - When excised, the cyst has a characteristic smell The primary risk factor for the development of SCC is - Most commonly, these get infected UV radiation exposure128; however, other risks - For infected epidermoid cyst, we give a course of include light Fitzpatrick skin type (I or II), antibiotics, and then excise environmental factors such as chemical agents, physical agents (ionizing radiation), psoralen, HPV-16 and -18 infections, immunosuppression, smoking, chronic wounds, Moh’s microsurgery 6. Trichilemmal Cyst Derived from the outer sheath of hair follicles They lack a granular layer They are almost always found in the scalp and in women The main purpose is to minimize the are of resection The tumor is mapped and divided into sections and then surgery is done via excision -> lab for frozen 7. Dermoid Cyst section of the tumor edges Congenital (-) histopathologic result: excision is stopped, and Occur as a result of persistent epithelium within then reconstruction is done embryonic lines of cushion Example: Tumor in the Nose Occur most commonly between the forehead, nose, teeth, and eyebrow (most frequent site) They can lie in the subcutaneous tissue or intracranially and often communicates with the skin surface via small fistula The cystic structure contain epithelial tissue, hair and a variety of epidermal appendages 2cm diameter - Subcutaneous tissue involvement NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 16 | 20  PCC SOM 2026 SURGERY 2 P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) Wide surgical excision including subcutaneous fat is Raised pearly pink papules, with telangiectasias the treatment of choice for SCC. Depressed tumor center with raised border – Sentinel lymph node dissection may be used in high “Rodent ulcer” risk cases with clinically negative nodal disease. Radiation therapy is typically reserved as primary therapy for those who are poor surgical candidates, and as adjuvant therapy after surgical resection for large, high-risk tumors Bowen’s Disease: in situ SCC - Confined to the epidermis - Characterized by full thickness epidermal dysplasia 2. Superficial Spreading Basal Cell Carcinoma - Clinically appears as a scaly erythematous patch often 15% with pigmentation and fissuring Pink erythematous plaque with thin pearly border Erythroplasia of Queyrat Slow-growing - Occurs in the glans penis Present in multiples Marjolin’s ulcer Confined to the epidermis as a flat, pink, scaling or - Malignant transformation of chronic ulcer can occur crusting lesion, often mistaken for eczema, actinic in any long standing moon keratosis, fungal infection, or psoriasis - De novo invasive SCC arising in areas of chronic Typically appears on the trunk or extremities and the wounds or burn scars are known as Marjolin’s ulcers, mean age of diagnosis is 57 years and have a higher metastatic potential Any wound that does not heal for a long period of time, patients are at risk of malignant transformation Treatment of BCC varies according to size, location, type, - Cancers arising de novo in chronic wounds include and high- or low-risk. Treatment options include surgical both squamous and basal cell carcinoma excision, medical, or destructive therapies. Surgical excision should include 4 mm margins for small, primary BCC on cosmetically sensitive areas, and 10 mm margins otherwise 3. Morpheaform Basal Cell Carcinoma Sclerosing/fibrosing BASAL CELL CARCINOMA Flat, yellowish, hypopigmented From the basal layer of non-keratinocytes Resemble scar Most common skin tumor True extent greater than physical appearance Associated with UVB>UVA Fingerlike extensions There is a propensity for a local invasion - Recurrence rate is high Causes immune suppression Chemical exposures Basal cell carcinoma (BCC) is the most common tumor diagnosed. BCC tends to occur on sun-exposed areas of the skin, most commonly the nose and other parts of the face. A malignant lesion on the upper lip is almost always BCC, and BCC is the most common malignant eyelid tumor. 4. Pigmented Basal Cell Carcinoma Types of Basal Cell Carcinoma Differential diagnosis: nodular melanoma 1. Nodular Basal Cell Carcinoma Most common (60%) NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 17 | 20  PCC SOM 2026 SURGERY 2 P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) intention but later on closed by primary intention. STEPS OF WOUND HEALING 1. Hemostasis Blood clot forms at the site of trauma → prevent further blood loss Affected blood vessels constrict Platelets aggregate (which are clood components for coagulation) to form platelet plug further reinforced by a protein called fibrin which forms the blood clot. 2. Inflammation Damaged cells release: Chemokines & Cytokines which recruit macrophage and neutrophils to the area and make nearby blood vessels Dilate Immune cells starts to seep into the affected area → starts to clear foreign debris Blood Clot + Dead Macrophages form a Scab (which form like a bandage) 3. Epithelialization - Migration REVIEW OF WOUND HEALING Basal cells (Stem cells in epidermis) start to Wound Healing proliferate & replace lost or damaged cells. Body repairs Damaged Tissue Takes about 48 hours and ends when the new Acute Wounds epidermal layer rejuvenates. - Heals Quickly (*Days-Weeks) But the New epidermal layer is weak because the Chronic Wounds strong dermal layer below has not regenerated. - Heals Slowly (*Months) 4. Fibroplasia Some tissue has the capacity to regenerate Wound becomes stronger & Damage resistant Fibroblasts - proliferate & secrete collagen in a TISSUE REGENERATION Classified as: process called Fibroplasia. 1. Labile Collagen assemble to form → Collagen Fibrils → Like the Skin, Connective tissue, and small & large Collagen bundles (which has high tensile strength intestine Heal Well and acts as Extracellular scaffolding) - Because they contain stem cells (undifferentiated Collagen also stimulates new blood vessels cells) (angiogenesis) 2. Stable Fibroblast produce glycoproteins & sugars → to Like the Liver - use mature differentiated cells to produce ground substance divide or regenerate via hyperplasia The Result of the processes mentioned: Creation 3. Permanent of granulation tissue Like the skeletal muscle, cartilage, neurons. 5. Maturation cardiac tissue have a weak regenerative capacity - Wound gets more support because they lack stem cells In these step, there is Collagen cross linking → Can cause fibrosis → leading to loss of function Covalent bonds form between collagen bundles - This process enhance the tensile strength of the SKIN wound Wound healing happens through: There is collagen remodeling 1. Primary Intention - Fibroblast degrade subpar collagen from the Wound edges come together injury. When wounds are stitched up together Contraction 2. Secondary Intention - Myofibroblast produce contractile proteins Wound edges = Too far apart - These contractile proteins attach to Wounds are left to heal by granulation transmembrane proteins Cells are replaced by connective tissue Repigmentation 3. Tertiary Intention - Melanocyte Proliferate Cleaned and left open just like secondary NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 18 | 20  PCC SOM 2026 SURGERY 2 P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) CHRONIC WOUND FACTORS 7. Neoplasms of epidermal keratinocytes that Capillaries become Narrow → decrease blood flow represent a range in a spectrum of disease from sun → Wound cannot heal properly → Necrosis damage to squamous cell carcinoma Causes of decrease blood flow: A. Seborrheic Keratosis - Diabetes B. Actinic Keratosis - Atherosclerosis C. Strawberry Hemangioma - Prolonged Compression 8. Derived from the outer sheath of hair follicles and Infections can also be a factor: are almost always found in the scalp and in women - Pathogens compete for O2 A. Neurofibromatosis - Cause damage & inflammation B. Epidermoid Cyst Edema can also be a factor: C. Trichelemmal Cyst - Fibroblast activity 9. 2nd most common skin cancer, associated with UV - Collagen deposition exposure - Cross-linking collagen A. Squamous Cell Carcinoma B. Basal Cell Carcinoma CHECKPOINT C. Lipoma 10. Common cause of surgical referral from critically ill 1. A rare mucocutaneous disorder characterized by patients cutaneous destruction at the dermoepidermal A. Extravasation Injury junction B. Chemical injury A. Hidrantis Suppurativa C. Pressure injury B. Epidermal Necrosis C. Erythema multiforme 2. Also known as acne inversa, can occur anywhere in the milk line and most found in the axilla and inguinal area for females A. Hidrantis Suppurativa B. Epidermal Necrosis C. Erythema multiforme 3. Type of Pyoderma Gangrenosum, with superficial variant that is more commonly found on the trunk as single or multiple, non-painful lesions. A. Vegetative B. Pustular c. Peristomal 4. Is an infection of the hair follicle that extends into the surrounding skin and deep underlying subcutaneous tissue. A. Cellulitis B. Carbuncle C. Furuncle 5. Benign vascular tumors that arise from the proliferation of endothelial cells that surround blood filled cavities A. Strawberry Hemangioma B. Cavernous Hemangioma C. Mixed Hemangioma 6. These are benign lesions of the epidermis that typically present as well-demarcated, “stuck on” appearing papules or plaques over elderly individuals A. Seborrheic Keratosis B. Actinic Keratosis 1.B 2.A 3.A 4.B 5.A 6.A 7.B 8.C 9.A 10.C C. Strawberry Hemangioma NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 19 | 20  PCC SOM 2026 SURGERY 2 P.01.02 SKIN AND SUBCUTANEOUS TISSUE (Part 2) NOTE TAKER: Agullana Challoy Ferrer Mariano Sangdaan Santiago Page 20 | 20