Block 7 Skin Creighton Univ Quiz Pt 2

The correct answer correctly orders the layers of skin from the outside inward. The layers of the skin, listed in order, are: stratum corneum, stratum granulosum, stratum spinosum, stratum basale, papillary dermis, and reticular dermis.

Hemangiomas are common, benign tumors that tend to affect females. They tend to regress after the first year. They require close monitoring, although they do not become malignant.

Not an all-inclusive list, but these are some key ones we've covered.

Tattoos have no association with skin cancer. Tanning beds have been conclusively shown to increase risk for melanoma.

Psoriasis does not affect the mucosae, but up to 70% of patients with lichen planus are affected on the mucosae. Answer A is a feature of both diseases, and B and D are characteristic of psoriasis alone. Dr. Shehan describes lichen planus as "pruitic, purple, polygonal papules".

Macule (1cm) are flat. Papules (1cm) are raised (ie palpable). Vesicles (0.5cm) are fluid-filled blisters.

SCC is better associated with p53 mutations. BRAF mutations are more characteristic of melanoma (in addition to CDKN2A).

Both rheumatoid arthritis and SLE are type III hypersensitivity reactions (immune complex). Answer A is type IV, C is type I, D and E are type II.

This pattern is Guttate psoriasis. It commonly occurs after a strep infection. Withdrawal of systemic steroids may induce pustular psoriasis. Nystatin can cause a delayed type IV hypersensitivity reaction, but the rash would appear as erythematous, weeping skin with vesicles. Frequent bathing may cause eczema.

A 10% KOH solution is used to dissolve keratin. This allows for easy identification of yeast and hyphae, fungus, and parasites such as mites or scabies. A Gram stain is most appropriate for bacteria.

Dr. Shehan was very clear in his lecture to not give systemic steroids because upon withdrawal the psoriasis may get worse.

Both answers A and B are from IgG antibodies. Acanthosis nigricans is hyperpigmentation, often in the axilla, and may be associated with visceral malignancy.

The physical sunscreens such as titanium dioxide and zinc oxide are those that reflect light across the spectrum. Cinnnamtes and PABA are for UVB. Benzophenones are for UVB and UVA2.

Renal toxicity is associated with cyclosporine. Acitretin, as with most retinoids, should be avoided in pregnant women. Methotrexate is a folic acid analog that causes antimitotic effects. Alefacept blocks T cells via the CD2 receptor.

UVA light has the longest wavelength, the lowest energy, and the best chance to penetrate the atmosphere. Answer B is UVB light, which is partially blocked. Answer C is UVC light which is almost entirely blocked.

Lotion is answer A.
Cream is answer C.
Ointments are mostly oil, which makes them best for dry skin.

After DNA damage, various proteins are involved in stopping the cell cycle to allow for repair. The p53 protein is a key regulator that can halt the cell cycle and initiate DNA repair mechanisms. ATR, another protein, is also involved in detecting DNA damage and activating cell cycle checkpoints to prevent further progression until repair is complete. Additionally, the p16 (ink4a) protein plays a role in cell cycle arrest and acts as a tumor suppressor. Therefore, all of the mentioned proteins (p53, ATR, and p16) are involved in stopping the cell cycle after DNA damage to facilitate repair.