Starting on 05/18: On Tuesday 05/19, write 250 words about what you've learned from the attached ppt.

The human skin is a major organ of our integumentary system and its main function is to act as a barrier and provide protection from mechanical impacts and pressure, variations in temperature, microorganisms, radiation and chemicals. It’s the largest organ in the body and serves as its protective covering. It’s the body’s primary defensive agent to prevent infectious organisms from entering the body. Additionally, the skin plays a significant role in thermoregulation and is vital in preventing overheating or overcooling of our body. As an organ, the skin can be divided into three separate zones: epidermis, dermis, and subcutis. The epidermis is the overlying squamous layer and is organized into further layers that is used when describing histological findings. In the most superficial layer of the epidermis, the horizontal elongation of keratinocytes continues and displays a loss of their nuclei. They continue to become less eosinophilic and less “pink”. This layer is called the stratum corneum. This is the most superficial layer and is an important clue not only to the presence of certain types of skin conditions, but also to their age. The next layer of the epidermis is known as the stratum spinosum. The deepest layer of the epidermis is the stratum basale, which is the site of mitosis and the home to melanocytes. The melanin pigment produced by these cells protects the skin from the sun as an increase in melanin correlates to higher pigmentation of the skin. The dermis is the layer of connective tissue and supporting structures that is directly beneath the epidermis. It is made up of collagen and elastic fibers that provide the tensile and elastic properties of the skin. The dermis is home to the three types of glands of the skin: sebaceous, eccrine, and apocrine. These glands are responsible for sweat and oil production as well as temperature regulation. Deep to the dermis is the subcutis, which is composed mostly of fat, blood vessels, nerves, and connective tissue.

• Alldredge, Brian K, Mary A. Koda-Kimble, and Lloyd Y. Young. Applied Therapeutics: The Clinical Use of Drugs. , 2013.

The powerpoint gave a comprehensive overview of the structure and function of skin. It refreshed my memory on the different layers of skin, their relationship between the classification of types of skin cancer, as well as various skin conditions. It first went on to define the different types of skin cells including basal cells and melanocytes. Then moving on to discuss the different layers of skin which are the epidermis, dermis, and hypodermis. The epidermis is the most outer layer of the skin and is made up of 5 different layers. Next, is the dermis, which is made up of both the papillary and reticular layer of connective tissue. Finally, we have the hypodermis which is the layer right under the dermis, connecting the skin to the underlying fascia of the bones and muscle. The hypodermis functions to provide insulation and fat storage to regulate temperature and protect the body from any injury. All in all, the 3 main functions of the skin is to act as a barrier and protect us, regulate different areas of physiology including body temperature, and it plays a significant role with our sensation.

As one of the most commonly diagnosed cancers in the United States and with most cases being preventable, skin cancer is a major public health problem. Together, basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma account for over 99% of skin cancers. BCC and SCC are considered non-melanoma skin cancers (NMSC). BCC is believed to be the most common type of skin cancer, whereas SCC accounts for about 20% of NMSC and is the second most common. Melanomas are the third most common, but likely the most serious type and also thought to be responsible for most skin cancer deaths. It was helpful to learn how to differentiate these skin cancers along with several others based on their unique signs and symptoms, causes, and treatments.

The last portion of the powerpoint discussed various drug-induced skin conditions erythematous reactions, SJS, TENS, angioedema, and several others. Angioedema which is a type of anaphylactic reaction can be caused by ACEI, such as lisinopril, captopril, and enalapril. Epinephrine is given to help protect the airways. Stevens-Johnson Syndrome (SJS) is a reaction that typically covers <10% of the body surface area (BSA), whereas Toxic Epidermal Necrolysis Syndrome (TENS) is characterized by a blister that generally encompasses >30% of the BSA. While both of these reactions are rare, they can be life-threatening. Both SJS and TENS can be caused by drugs such as allopurinol, carbamazepine, hydantoin, and fluoroquinolones. They are also both managed with fluid replacement, prevention of infection, thermal control, skin and pulmonary care, and adequate analgesics.

Reference:

US Department of Health and Human Services. The Surgeon General's Call to Action to Prevent Skin Cancer. Washington (DC): Office of the Surgeon General (US); 2014. Skin Cancer as a Major Public Health Problem. Available from: https://www.ncbi.nlm.nih.gov/books/NBK247164/

The skin and its other structures make up the integumentary system. The skin consists of layers of cells and tissues, and its main function is to act as a barrier to protect the body from various types of damage. It also helps regulate body temperature with sweat and hair, produce vitamin D, and help us feel sensation. The different types of cells present in the skin are basal cells, keratinocytes, melanocytes, merkel cells, and Langerhans cells.

The skin is made up of the epidermis, dermis, and hypodermis. The epidermis is the outermost layer or surface epithelium of the skin. The dermis is the thick layer underneath the epidermis; it contains blood and lymph vessels, nerves, and other structures like hair follicles and sweat glands. The hypodermis, otherwise known as the subcutaneous layer, lies underneath the dermis and connects the skin to the underlying fascia of bones and muscles. It consists of mostly adipose tissue and functions to provide insulation and fat storage.

Dermatologic conditions include skin cancers, drug-induced conditions, and others such as eczema, psoriasis, acne, ringworm, etc. The skin is a common site for adverse drug reactions. Drug-induced skin reactions can be irritant or allergic in nature. Allergic reactions induce an immune response, and are categorized by the type of eruptions (exanthematous, urticarial, blistering, or pustular). Some can even be life-threatening such as SJS/TEN, which cause blistering eruptions. When a drug-induced skin reaction is suspected, the first course of action is usual to discontinue the offending agent as quickly as possible. Further management includes symptom control and supportive measures. In SJS/TENS, fluid and electrolyte balance, infection prevention, thermal control, eye/skin/pulmonary care, and proper analgesic are important.

Reference:

Law RM, Law DS, Maibach HI. Dermatologic Drug Reactions, Contact Dermatitis, and Common Skin Conditions. In: DiPiro JT, Yee GC, Posey L, Haines ST, Nolin TD, Ellingrod V. eds. Pharmacotherapy: A Pathophysiologic Approach, 11e New York, NY: McGraw-Hill.

Skin and the other structures make up the integumentary system. The skin has various roles such as protection, regulation and sensation. The skin acts as a barrier to chemicals and prevents damage from the UV rays. The skin also regulates the body temperature and helps us feel and touch due to the presence of nociceptors. The skin is made up of different types of skin cells such as basal cells, keratinocytes, melanocytes, merkel cells and langerhans cells. The skin also has many different layers, of which epidermis is the outermost layer of the skin. Within the epidermis, it contains 5 different layers which consists of Stratum Basale, Stratum Spinosum, Stratum Granulosum, Stratum Lucidum, and Stratum Corneum. Next, the skin has a layer called dermis, which is the core layer of the integumentary system. Hypodermis is another layer, which is known as the subcutaneous layer and connects the skin to the bones and muscles. Moreover, the color of our skin is based on different factors such as melanin, carotene and hemoglobin. Getting a brief overview of the skin, this powerpoint then went into the different types of skin cancers such as basal cell carcinoma, squamous cell carcinoma, melanoma, merkel cell carcinoma, CTCL, DFSP, and sebaceous carcinoma. BCC is the most common type of skin cancer and can be treated if found early. It happens in areas where there was a lot of sun exposure (face and ears). It can be treated with radiation, or medications (imiquimod, 5-FU). Melanoma is often known to be the most serious type of cancer and can spread from the skin to other parts of the body. ABCDEs of melanoma are asymmetry, border, color, diameter, and evolving. Other skin conditions such as angioedema can occur, which is an anaphylactic reaction due to certain medication use (ACEI). This leads to edema of the lips, tongue, eyelids and can be fatal. Treatment is to stop the offending agent and use epinephrine for airway support. SJS/TENS is another skin condition that is a very rare reaction but can occur when using certain medications. They both occur from medications such as allopurinol, carbamazepine, fluoroquinolones, phenytoin, long acting sulfonamides, etc. The difference between SJS and TENS is that SJS occurs on <10% of your BSA, whereas TENS is >30% of your BSA and is considered more severe. Many other commonly occurring skin conditions are eczema, psoriasis, rosacea, acne, vitiligo, shingles, etc.

Reference: -https://opentextbc.ca/anatomyandphysiology/chapter/5-1-layers-of-the-skin/