Derm Flashcards
What is scabies?
Scabies (“the itch”) is an infestation of the skin by the mite Sarcoptes scabiei that results in an intensely pruritic eruption with a characteristic distribution pattern.
How is scabies typically distributed?
- sides and webs of the fingers,
- flexor aspects of the wrists
- extensor aspects of the elbows, anterior and posterior axillary folds, the skin immediately adjacent to the nipples (especially in women), the periumbilical areas, waist
- male genitalia (scrotum, penile shaft, and glans), the extensor surface of the knees, the lower half of the buttocks and adjacent thighs, and the lateral and posterior aspects of the feet.
- The back is relatively free of involvement, and the head is spared except in very young children. Rarely, may be localized to a single area
Clinical characteristics of scabies
- **itching. often severe and usually worse at night.
- * small, erythematous, nondescript papule, often excoriated and tipped with hemorrhagic crusts (not dramatic lesion and not always easy to see.
- Burrow is pathognomonic. thin, grayish, reddish, or brownish line that is 2 to 15 mm long. (Often absent or obscured by excoriation or secondary infection)
- * Miniature wheals, vesicles, pustules, and rarely bullae may also be present.
- * Magnify the lesion – will see burrow, seripigenous lesion, can use india ink dye test (usually in derm)
- Crusted - suggests immunodeficiency (look for RFs for HIV)
- * Can be nodular
Why does scabies itch?
- * delayed type-IV hypersensitivity reaction to the mite, mite feces, and mite eggs
- * 3 to 6 weeks after primary infestation
- * UNLESS previously infested with scabies: one to three days after reinfestation, presumably because of prior sensitization of the patient’s immune system
Treatment for scabies
Ivermectin oral or Permethrin topical
What is post scabetic dermatitis?
No longer infected but still having immune response to scabies. Will go away as skin sheds.
Treatment of postscabetic dermatitis
Comfort care
Atarax, topical steroids or other anti-itch creams
How crazy do patients have to get about washing/bagging all their linens/clothes/etc?
- mites survive only 2-3 days away from human skin
- clothing and linens used within the preceding few days should be washed in hot water and dried in a hot dryer or bagged for several days.
Clinical characteristics of bed bugs
- face, neck, hands, and arms
- may be noticed upon awakening or one to several days after the bites
- small punctum without a surrounding reaction. May have only asymptomatic purpuric macules.
- Lines of 3: not always linear
- usually pruritic
- History of travel, new furniture
Treatment for bed bugs
- get rid of stuff, fumigate
- hard to get rid off
- Symptomatically – topical steroids, atarax, orals steroids if very severe
- Psychological support
What is Morgellons Syndrome?
- What is another word for this?
- aka Delusional parasitosis
- fixed, false belief (delusion) that they are infected by “bugs”: parasites, worms, bacteria, mites, or other living organisms
- Delusion disorder, believes they have bug/aprasite but there is nothing there.
- See itchiness, patches of skin being ripped off, no bite marks.
- technically, Morgellons is a lay term for Delusion Parasitosis + beliefs of inanimate objects in the lesion as well (such as colored strings or fibers)
- named and described in 1674 by Sir Thomas Browne. The term “Morgellons disease” has been adopted by an active community of patients and family members on the internet who believe that this unexplained dermopathy is a poorly diagnosed infectious disease and dispute an underlying psychological basis.
Treatment for delusional parasitosis
- Atarax, anti-itch creams, anti-psychotics - only to help with QOL
- A lot of tx is about gaining trust.
- Tell them s/s are real, we don’t know what is causing it, manage s/s to give best quality of lfie
- May eventually find a cause for what these people are experiencing, but for now considered delusional do
- Oatmeal baths can also help.
- -s/s management
- Empathy exam
- Itch impacts QOL as much as pain
- Palliative care
- Anti itch cream – topical steroids – sarna lotion or topical benadryl
- Oatmeal bath
What is urticaria?
- AKA Hives
- A skin rash that results from the release of histamine.
- Can be acute = less than 6 weeks
- Or it can be chronic
Causes of urticaria
- Food allergy
- Drug induced: especially sulfa, PCN
- Parasites
- Poison ivy, poison sumac
- Dermatographic
- Stress or cholinergic
- Cold or heat induced
- Solar
- Exercise - stress induced
- Water
- Autoimmune thyroiditis
- Infections- especially strep and viral (if fever, consider)
Work up for urticaria
- Allergy panels (Immunocap)
- TSH, Free T4, Anti-thyroid peroxidase antibodies, thyroglobulin level (660 kDa, tumor marker for tx thyroid CA)
- Histamine release
- CBC - check for infection
- strep test (if applicable)
- blood screening for viral infections (if applicable)
- testing for parasites (if applicable)
Treatment for urticaria
- Avoid the cause if possible.
- Treat underlying infection if applicable.
- Medrol dose pak (if infrequent or acute).
- Anti-histamines.
- Doxepin (good anti-itch cream usually covered by insurance $$$)
If chronic - don’t give steroid. Only give when it is acute urticaria/hive.
What are Tinea corporis, pedis, cruris, capitus?
Fungal infection of the skin (dermatophytes)
- Corporis: body
- Pedis: feet
- Cruris: groin and adjacent skin
- Capitus: scalp
How do the tineas present?
- hyperpigmented plaques, Annular patches, crust.
- Pruritic.
- Feet: most commonly presents in the toe web as erosions. Can present as blisters as well (atypical).
-Can be atypical s/s with blisters on their feet all sudden
Treatment for tineas
Topical antifungal. If hair follicle involvement will need oral.
- Oral ketoconazole Black Box Warning bc adverse effects – only for severe life threatening infections in bloodstream
- **If initially treated w/ steroid, develop odd lesions –> tinea incognito - makes more difficult to Dx.
- Diminished erythema and scale, loss of a well-defined border, exacerbation of disease, or a deep-seated folliculitis (Majocchi’s granuloma)
- Lamasil???
- supresses immune sys and goes away but if you just use steroid, it will come back full force after going away
- Steroid can exacerbate. And if it goes away you don’t know what it truly was.
- -Ketaconzole – is black box now! Only severe, life threatening fungal effects!!!!
What is Dishydrotic eczema?
***exam
Type of eczema characterized but vesicular or papular eruptions on the palms and soles. Triggers can include hot water, nickel, allergens.
Lean towards this if, eg. Washing dishes a lot
Treatment for dishydrotic eczema
Topical corticosteroids. Avoidance of triggers.
Feet – dx think of tinea
-Take skin scrapping, KOH, look for deraphayte
What is Lichen simplex chronicus?
- A skin disorder characterized by scaling and skin thinning resulting from repetitive scratching
- Creates a scratch-itch cycle
- Plaque from scratching too much
- So it is forming a callous, common elderly
Treatment of lichen simplex chronicus
Anti-itch medication, topical steroids, emollients and lotions, behavior modification
Hydrocolloid dressing on small area so that cannot scratch
- -Can do that with silicone /gental borders.
- Elderly common
What is psoriasis?
***exam
autoimmune disorder resulting in excessive growth of the skin.
How does psoriasis present?
- Classically presents as a salmon colored plaque with scale on extensor surfaces, umbilicus, groin and scalp
- can also present as pustules and vesicles
- Nails will have pitting.
- May develop arthritis as well, which is called psoriatic arthritis.
- Psoriasis severity index can be used to evaluate.
Risks associated with psoriasis
Associated with arthritis, increased cardiovascular risk, risk of inflammatory bowel, ankylosis spondylitis, SCC and lymphoma.
Treatment of psoriasis
- Topical corticosteroids, dovonex, protopic.
- If extensive- biologics like Remicaid and Humira
-
Methotrexate: particularly in psoriatic arthritis
- can cause fibrosis in lungs, issues with liver
- phototherapy
- No tattoos, trauma may cause outbreak (Koebner phenomenon).
- No treatment with oral corticosteroids (initially helpful, but comes back worse)
- Supportive: beach - salt water and sun, but avoid sunburns
-If COPD/asthma is risk benefit analysis bc psoriasis is worse at the end w ICS
Lichen sclerosis: cause
unknown- some research indicates that may be associated with thyroid disease.
Lichen sclerosis men vs women
women more than men (10:1)
Occurs more frequently around and after menopause
Clinical presentation of lichen sclerosis
- Usually genitalia and anus, can be located on the upper thigh
- Ivory white raised plaques, may have itching, may cause genitalia to shrink- which can cause pain during intercourse/urination/defecation
- -Can be a plaque.
- Can be pain/itching.
- Uncircumsized male can get phimosis.
- In men, may develop into phimosis (tight foreskin can’t be pulled back over the head of the penis)
lichen sclerosis: treatment
High potency topical steroids (Clobetasol)
educate pt to watch out for yeast infections
What is intertrigo?
Yeast infection in skin folds caused by excess moisture
More common in obesity, diabetes, and with advanced age
Yeast infection to the skin
-Yeast in skin + excess moisture + diabetes (high glucose w issues of immune) – yeast overgrowth = infection
Appearance of intertrigo
Skin is red, denuded, tended may have satellite lesions and an odor.
Treatment for intertrigo
Avoidance of moisture. Antifungals.
Nystatin powder, Desitin cream (zinc oxide)
Interdry-ag is a textile with silver component but is very expensive
- -Textile – interdry Ag – keeps skin dry with silver component but expensive .
- Tx: lotrimin (anti fungal) Lotrisone, Nystatin.
- Very severe and topical not working – go with oral nystatin
Clinical characteristics of lichen planus
- Itchy violaceous rash.
- Oral lesions common: tends to be lacy, white, side of mouth
- May cause nail and hair loss.
- Cause is unknown.
5 Ps of Lichen Planus
* pruritic
* planar
* purple
* polygonal
* papules and plaques
are additionally well-defined
Treatment for lichen planus
* Oral and topical steroids
* Protopic or Elidel
* Phototherapy
* Oral retinoids tends to be difficult to treat
What is Seborrheic dermatitis?
inflammatory skin condition caused by a combination of a pathological over production of sebum combined with fungal overgrow.
What to consider if seborrheic dermatitis is severe new onset in adult?
work up for immune disorder such as HIV.
Also associated with Parkinson’s and MS.
Parkinson’s - likely 2/2 lack of facial muscle mvmt - overgrowth
Treatment for seborrheic dermatitis
Topical antifungals. Topical steroids. Protopic.
What is Atopic dermatitis?
***exam
Inflammatory skin disorder associated associated with other atopic diseases such as allergy and asthma
Clinical characteristics of atopic dermatitis?
***exam
- Lichenification (hardened), papules, crust on flexor surfaces and cheeks common.
- Onset is typically in childhood usually improves with age
- if new onset n adult think of cancer *
- *if only one area: consider fungal
Differences in atopic dermatitis kids vs adults
***exam
- 0-2yo: pruritic, red, scaly, and crusted lesions on the extensor surfaces and cheeks or scalp, sparing diaper area
- 2-16yo: less exudation and often demonstrates lichenified plaques in a flexural distribution, especially of the antecubital and popliteal fossae, volar (palm/sole) aspect of the wrists, ankles, and neck (“dirty neck”)
- Adults: considerably more localized and lichenified. Skin flexures. Face, neck, and hands less frequently affected.
Treatment atopic dermatitis
Topical steroids. Protopic/Elidel. Emollients/ lotions.
Avoidance of triggers. Treatment of allergens.
Clinical characteristics of tinea versicolor?
- Caused by Malassezia yeast.
- Hyper or hypopigmented patches and plaques over sebaceous areas (Hypo more in darker skin, hyper/erythematous in lighter)
- Tends to relapse in hotter months or if sweating more
- Will relapse: natural yeast on body
Treatment and prevention for tinea versicolor
Cotton t-shirts. Topical antifungals. Topical steroids. Oral antifungals. Ketoconazole or selsen shampoos.
can help with the skin coloring but can make worse
Prevention: dose of conazole per month, steroid cna help get rid of pigmentation
Clinical characteristics of pityriasis rosea
- Starts as a large patch on the trunk called a herald patch with collarette scale then smaller patches and plaques appear on the trunk and out to the extremities
- Usually takes on a Christmas tree pattern.
- Pruritic (often)
What is actinic keratosis?
Caused by?
Size?
Clinical characteristics/progression
****Exam
Pre-malignant condition characterized by scaly or crusty patches of skin over sun exposed areas.
Start as flat scaly areas and progress to wart-like areas. Range between 2-6 mm in size. Caused by sun exposure.
What is solar lentigo?
Aka liver or age spot
Hyperpigmentation from age and sun exposure
What is seborrheic keratosis?
Clinical characteristics/cause
- Noncancerous benign skin growth. More common in elderly. But still occur in the young
- No association with sun exposure
- Hyperpigmented papules with a warty and “stuck on” appearance.
- Cause is genetic.
What is basal cell carcinoma?
clinical characteristics
****Exam
- Skin cancer affecting the basal layer of the epidermis
- Classic is a pearly nodule with pedunculated center and telangectasia running through
– indented in the middle and can ulcer over time
Note:
telangectasia = dilation of the capillaries, which causes them to appear as small red or purple clusters, often spidery in appearance, on the skin or the surface of an organ.
What is squamous cell carcinoma?
clinical characteristics
****Exam
A skin cancer of the squamous cell of the epithelium.
Can have a variety of presentations:
- Common presentations: Firm red nodule, flat lesion with a scaly crust, a new ulceration in a scar or ulcer, rapidly expanding mole or keratotic lesion, change in mole color- especially varigation
- Non-healing ulcer without other probable cause (Marjolin’s ulcer)
- Bleeding or expanding lesion on the lip or mouth
ANY AREA LIP – BLEEDING EXPENDING - doesn’t look like sore = painless ulcer w middle age older = SCC!
What is melanoma?
Clinical characteristics
****Exam
- Malignant cancer of the melanocytes
- Spreads rapidly
- Presents as a change in size, shape and color to an existing mole or new “lump” on the skin if nodular
- Use the ABCDE rule with E being evolving when evaluating moles
- Also can use the ugly duckling rule
- Common in young adults too!
This is the most dangerous skin cancer = Malignant!!!
- greater than 6 mm, and can be under the nail!
What is cutaneous lymphoma
****Exam
Skin manifestation of lymphoma (cancer of the B and T lymphocytes)
- T- cell lymphoma may have the appears of atopic dermatitis without the distribution pattern, atopic history, or history of dermatitis in childhood. May also appear to be fungal disease.
What is Keratoacanthoma?
- Pre-cancerous nodule, typically occurring on the leg (however some consider it to be a low grade SCC). 6% will become SCC if untreated. Primarily in elderly
- Domed shaped nodule with scale on top- grows rapidly.
- Differentials include SCC and BCC
What are fungating wounds?
* Advanced breast, head and neck cancers, also labial cancers
* Odorous, painful, highly exudative, bleed often
pallative care!
What is a Nevus sebaceous?
-Congenital hairless plaque that starts off as smooth at birth. When the individual reaches puberty, the lesion increases in size and takes on a warty appearance. Found on scalp and face.
Mostly in teenager
- Skin colored, at puberty, get warty looking
- Controversial whether it will become bcc.
- Up to them if they want it removed for cosmetic reasons or prophylactic
What is impetigo?
clinical characteristics
- Superficial staph (usually- rarely can be strep) infection involving the epidermis. Highly contagious.
- Can occur as a suprainfection from herpes or other lesions.
- Can start as vesicles. General appears as honey colored crusted scabs on the face, arms or legs.
Clinical characteristics of contact dermatitis?
****Exam
Inflammatory skin condition due to contact with a substance. May be irritant, allergic or photocontact.
Lesions may be in the shape of the item in contact with the skin. May be erythematous, blisters, papules, wheals or plaques. Frequently pruritic.
What is acne rosacea?
Clinical characteristics
****Exam
- Chronic inflammatory condition involving facial erythema, telangectasias, nodules, and pimples
- May develop nodules or alterations to the shape of the nose over time (rhinophyma- example is Churchill)
- Many triggers
- May co-exist with seborrheic dermatitis and acne vulgaris
What is Erysipelas?
Clinical characteristics
- A skin infection of the upper dermis caused by strep.
- Characterized by high fevers, chills, shaking, HA and malaise in the first 48 hours.
- Skin lesion is erythematous plaque that enlarges rapidly and has a sharply demarcated raised edge. It appears as a red, swollen, warm, hardened and painful rash with a peau d’orange appearance.
What is hidradenitis suppurativa?
Clinical characteristics
- Disease of the apocrine glands resulting in the formation of large, sometimes painful, cysts or abscesses
- In axilla, groin, chest, breasts, inner thighs and buttocks
What is erythema nodosum?
clinical characteristics
* An inflammation of the fat cells.
* Tender red nodules on the skin- typically the lower extremities.
* Resolves in 3-6 weeks.
What is Alopecia areata?
-Autoimmune disorder causing round patches of hairloss.
What is Androgenic/ androgenetic hair loss?
* AKA male pattern baldness
* Occurs in men and women
* Hair loss begins at temples and also at the crown of the head
What is Scarring alopecia?
* Hair loss that occurs when the follicle is destroyed and replaced by collagen (scar).
* May be primary (lymphocytic or neutrophilic) or secondary.
* Secondary cause: traction alopecia, lupus, scleroderma
scleroderma = (systemic sclerosis, is a chronic connective tissue dz,autoimmune rheumatic = hardening/tightening of skin)
What is Dissecting cellulitis of the scalp?
Who does it affect?
- A type of primary neutrophilic scarring alopecia.
- Chronic perifollicular pustules, nodules, cysts on the scalp than result in scaring and alopecia
- Areas of fluctuance, pustules, and nodules on the scalp.
- Depending on how long they have had it, you may see scars and alopecia.
- Men of African descent in the 2nd-4th decades of life 20s-40s
- Cause not clearly known
What is traction alopecia?
* A type of secondary scarring alopecia caused by pulling forces or traction.
* Key is history- ask about recent hairstyles.
* Common culprits: ponytails, braids, barrettes, hair weaves
Cutaneous horn characteristic and causes
Hyperkaratotic skin lesions that take conical shape.
Caused by DNA Damange from sunlight, radiation, HPV.
