Dermatology I

Acne Vulgaris Pathophysiology: 4 main factors:

hyperkeratinization, increased sebum, cultibacterium acnes overgrowth, and inflammatory response

Acne Vulgaris Tx mild comedonal Acne

1st line: topical retinoid monotherapy

ex: tretinoin, adapalene, tazarotene,trifarotene

S/E: erythema,dryness, flaking,pruritus, stinging

alternatives: azelaic acid,salicyclic acid, glycolic acid

Acne Vulgaris Tx mild papulopustular and mixed acne

1st line: topical retinoid and topical antimicrobial

options: benzoyl peroxide +- clindamycin

alternatives: benzoyl peroize + toical antibitoic or topical dapsone

Acne Vulgaris Tx Moderate

consider systemic therapy (oral antibiotics,hormonal agents, oral isotretinoin)

oral antibiotics: always combine w benzoyl peroxide to reduce resistance. limit to 12 weeks. 1st line minocycline and doxycycline

oral contraceptives can be used to tx inflammatory or noninflammatory acne in women w adult onset acne or perimenstrual flare ups.

Acne Vulgaris Tx severe

isotretinoin-teratogenicity so must be on oral contraceptives or signed pledge prior to initiating period adverse effects include dry skin comma cracked lips comma increase triglycerides and cholesterol comma and possible psychiatric effects like depression and suicidial ideation period.

Rosacea

Adult acne

More common in women

H&P: flushing, persisent erythema, telangiectasias, papulopustular lesions;ocular symptoms. absence of comedone and presence of neurovascular symptoms (flushing,feeling of warmth or burning or stinging sensation) distinguish rosacea from acne. phymatous change: rhinophyma (enlarged nose)

Rosacea Tx

1st step: lifestyle modifications, avoid triggers-(alcohol, hot/cold weather, hot drinks, hot baths, spicy food, sun exposure

Mild-moderate papulopustules: topical metronidazole, azelaic acid, ivermectin

moderate to severe papulopustules:oral tetracycline,doxycycline,laser for telengiesctasias.

facial erythema: topical brimonidine 0.33% gel

Folliculitis

Inflammation of a hair follice

Bacterial S. aureus most common cause;or fungal causes; hot tub exposure (psuedomonal folliculitis; commonly seen after hot tub, pool contamination)

H&P: single or clusters of perifollicular papules or pustules w/surrounding erythema at base of hair, often pruritic.

Folliculitis Tx

gentle cleansing, compresses.

mild: mupirocin (bactroban), topical clindamycin.

in more severe cases, oral antibiotics may need to be used (Keflex, Doxy). Fluroquinolone if hot tub folliculitis is severe (ciprofloxacin).

Folliculitis

Perioral dermatitis

Associated w topical steroid use.

H&P: Erythematous papules/pustules around mouth and periorificial areas sparing vermilion border.

Perioral dermatitis Tx

stop topical steroids, avoid skin irritants like makeup/skin products, topical metronidazole or pimecrolimus, oral tetracyclines if needed. oral tetracyclines if severe.

Perioral dermatitis

Acanthosis nigricans ON TEST

associated w obesity (most common cause), insulin resistance, and malignancy in adults (rarely-gastric adenocarcinoma, uterine, lung,breast, ovarian)

Pathophysiology: Insulin/IGF-mediated keratinocyte proliferation causing hyperpigmented VELVETY plaques.

H&P: Symmetric hyperpigmented velvety plaques in neck/skin folds.

Acanthosis nigricans TX ON TEST

Treat underlying cause, weight loss, topical retinoids, or vitamin D analog (calcipotriene) for faster resolution.

Acanthosis Nigricans

Hidradenitis suppurativa (Acne Inversa)

Pathophysiology: follicular occlusion/obstruction leading to inflammation,sinus tracts in apocrine-bearing areas and intertriginous areas (axilla most common)

H&P: painful inflamed nodules, abscesses, draining sinus tracts in axillae/groin.

Smoking/obesity are risk factors

Hidradenitis suppurativa (Acne Inversa) TX

Hygiene,weight loss, lifestyle changes

Hurley stages:

I: topical clindamycin first line,oral tetracycline if no improvement

II: oral doxy first line

III: clindamycine + rifampin

if above fail: consider biologics, wide surgical excision as last resort.

Hidradenitis suppurativa (Acne Inversa)

Hidradenitis suppurativa (Acne Inversa) 3 STAGES

Hurley stages:

I: inflammatory lesions WITHOUT sinus tracks or scarring

II and III= inflammatory lesions WITH tracs and scarring

Lipomas

Benign, soft, mobile, any size

Lipomas

Epidermal Inclusion Cysts

Benign encapsulated subepidermal nodules filled w/fibrous tissue and keratinour (cottage cheese like) material. cysts result from plugging of folliculat orifices. original from the epidermis.

Pathophysiology: follicular occlusion w keratin-filled cyst (thick,cheesy)

H&P: FIRM, MOBILE NODULE W CENTRAL PUNCTUM (DARK COMEDONE OPENING); CAN BECOME INFLAMED/INFECTED. RUPTURED, INFECTED SYSTS; FLUCTULANT, PAINFUL, LARGE, ERYTHEMATOUS, FOUL SEMLLING YELLOWISH CHEESE-LIKE DISCHARGE.

Epidermal Inclusion Cysts TX

Observation, incision and drainage for acute infection, surgical excision for definitive treatment (usually done when not infected)

Epidermal Inclusion Cysts

Photosensitivity reactions

Pathophysiology: UV- triggered skin reaction via phototoxic or photoallergic mechanisms.

H&P: sun-exposed distributions of erythema, blistering, or eczematous lesions

Photosensitivity reactions TX

avoidance, photoprotection, topical steroids, stop offending drug

Pilonidal disease (cyst)

Pathophysiology: hair penetration and foreign body reaction in natal cleft leading to sinus formation.

H&P: painful medline sacrococcygeal abscess or draining sinus

Pilonidal disease (cyst) TX

Incision & drainage for acute abscess, surgical excision for chronic disease; hair removal measures

Pilonidal disease (cyst)

Urticaria (Hives)

Histamine related increased vascular permeability.

Common; acute often post-infection or drug;chronic > 6 weeks in some

Pathophysiology: release of vasodilators (histamine,bradykinin,prostalgnadins) from mast cells and basophils in the skin.

H&P: Pruritic transient wheals with central pallor; angiodema possible.

Urticaria (Hives) TX:

2nd gen antihistamines H1 blockers as less sedative ; consider sedating H1 antihistamine at nighttime in healthy individulas. avoid triggers, oral corticosteroids for severe flares. epinephrine if concern for airway compromise.

Urticaria (Hives)

Hyperhidrosis

Pathophysiology: overactivity of eccrine glands; sympathetic overactivity

H&P: excess focal sweating (palms,soles,axillae) impairing daily activities.

Hyperhidrosis TX

Topical aluminum chloride, iontophoresis,botulinum toxin, anticholinergics, surgery

Eczema

Pathophysiology: skin barrier dysfunction and inflammation

H&P: pruritic,erythematous,scaly patches; distribution depends on type.

Eczema TX

Emollients, topical steroids, treat triggers, and infections

Atopic dermatitis

Pathophysiology: barrier dysfunction, disordered immune response

Atopic traid: atopic dermatitis (eczema) + allergic rhinitis + asthma

H&P: pruritic, exzematous lesions in FLEXURAL areas

Atopic dermatitis TX

Chronic management: restore skin barrier/maintain skin hydration (skin emollients BID and within 3 mins of exiting bath. pat skin, dont rub dry.

Pruritis: nonsedating antihistamines

avoid triggers: heat, perspiration, wool, nickel,foods, allergens

Acute management:

topical corticosteroids first line often used w/emollients. antihistamines for itching. west dressings.

topical calcineurin inhibitor (tacrolimus,pimecrolimus) alternative to low potency steroids on face or skin folds

Moderate to severe disease: phototherapy, dupilumbad

Atopic dermatitis

Dyshidrotic eczema

affects palms/soles; recurrent

pathophysiology: unknown; possible atopic association and sweat-related triggers.

H&P: pruritic vesicles on lateral fingers, palms, soles.

Dyshidrotic eczema TX

topical steroids, emollients, cold compresses; severe cases may need systemic therapy

Dyshidrotic eczema

Contact Dermatitis

Pathophysiology: Irritant:direct damage. allergic:delayed hypersensitivity (type IV).

H&P: Erythema, vesicles, pruritus in exposed distribution.

Contact dermatitis TX

AVOIDANT MEASURES, EMOLLIENTS, TOPICAL STEROIDS; FOR ALLERGIC IDENTIFY/REMOVE ALLERGEN

Drug eruptions

pathophysiology: immune-mediated or toxic drug reactions.

H&P: morbilliform rash commonl can be urticarial, fixed, or severe (eg., SJS/TEN).

Drug eruptions TX

Stop culprit drug, supportive care; systemic steroids for severe reactions.

Lichen Planus

autoimmune disorder in patients with a genetic predisposition but may be caused by medications or be associated w disorders such as hepatitis c.

Lichen Planus 6 p’s

Purple, polygonal, planar, pruritic (itchy), papules, plaques w/fine scales

Lichen Planus- wickham striae

fine gray white lines on the skin lesions or oral mucosa mucosal involvement possible.

Lichen Planus TX

topical/systemic steroids (high or super high potency) is mainstay tx of LP w/occulsive dressings for trunk and extremity; intralesional corticosteroids for hypertrophic LP, retinoids, immunosuppressants for refractory disease.

Lichen Planus

Pityriasis Rosea ON TEST

Pathophysiology: likely viral (HHV-6/7) association.

H&P: Herald patch (solitary salmon colored, red or brown macule) followed by CHRISTMAS-TREE trunk distribution of oval scaly plaques. pruritis common but mild. usually confined to trunk and proximal extremities.

Pityriasis Rosea TX

no management needed for most.

supportive: emollients, topical steroids, oral antihistamines, oatmeal baths for pruritus; resolves in week-months.

Pityriasis Rosea

Psoriasis ON TEST

autoimmune related

chronic management

pathophysiiology: keratinocyte hyperproliferation. this results in greater epidermal thickness and accerlaerated episdermis turnover.

H&P: well-demarcated erythematous plaques w/ silvery scale; nail changes; possible arthritis. plaques most common on EXTENSOR surfaces of elbows, knees,scalp,nape of the neck, gluteal cleft.

Psoriasis common signs ON TEST

Auspitz sign- bleeding w/removal of plaque or scales.

Koebners phenomenon-new lesions at the site of trauma

Nail involvement- nail pitting; yellow-brown discoloration under the nail (oil spot) is pathognomonic.

Psoriasis TX ON TEST

mild moderate:

limited disease: topical corticosteroids, emollients, maintain proper skin hydrate to help prevent irritation

Alternative topical agents: vitamin D analogs, retinoids/vitamin A analogs

Topical calcineurin inhibitors (tacrolimus, pimecrolimus: use for involvement of face, genitals, delicate areas.

Moderate-severe:

Phototherapy: narrow-band UVB

Severe:

Systemic tx: cyclosporine, oral retinoids (acitretin), biologic agents (tnf-inhibitors). inhibitors of the IL-17 pathways and IL-23. methotrexate.

Psoriasis ON TEST

Seborrheic dermatitis

Pathophysiology: malassezia species, sebum, and host response

H&P: erythematous, greasy scales in seborrheic areas.

Seborrheic dermatitis TX

antifungal shampoos/creams, topical steroids for flares, ultraviolet radiation, ketoconazole and selenium shampoo

Seborrheic dermatitis

Erysipelas

Pathophysiology: superficial dermal lympathic infection

group A strep

H&P: well-demaracted, raised erythematous plaque w systemic symptoms.

Erysipelas TX

Penicillin or appropriate antibiotics for streptococcal coverage

Erysipelas

Cellulitis

Infection of the skin happens w a breach in integrity of the skin.

Lower extremities are the most common site

beta hemolytic streptococci

staph aureus

Cellulitis

Impetigo ON EXAM

Superficial epidermal infection w HONEY-COLORED CRUSTS.

H&P: vesicles/pustules that rupture forming crusts; pruritic.

Impetigo TX ON EXAM

Topical mupirocin for limited disease; oral antibiotics for widespread disease.

Impetigo ON EXAM

Candidiasis

Anywhere you have body folds

Pathophysiology: overgrowth of candida species

H&P: erythematous, moist patches w satellite pustules.

Candidiasis TX

Topical or oral azoles; address predisposing factors.

Candidiasis

Fungal-Dermatophyte infections

epidemiology: tinea corporis,pedis,capitis

Pathophysiology: keratinophilic fungi invade stratum corneum

H&P: annular, scaly plaques w central clearing (ringworm); pruritus.

Fungal-Dermatophyte infections TX

topical or oral antifungals depending on site and severity

Tinea Versicolor

Caught by yeast, found in the upper layer.

Fungal infection of the skin with overgrowth of Malassezia yeast

H&P: hyper or hypopigmented well demarcated round or oval macule or patch that can have erythema and a fine scale. most common on upper trunk. involved skin fails to tan w sun exposure.

Tinea Versicolor TX

topical antifungals, ketaconazole, selenium sulfide lotion

Lice

pathophysiology: pediculus species infestation of hair/scalp or body.

H&P: Pruritus, nits on hair shafts.

Lice TX

topical permethrin or oral ivermectin;treat contacts and fomites.

Pediculosis Corporis

Pediculosis pubis

crabs result from sexual contact

itching in pubic area but also in axillae

Pediculosis pubis tx

permethrin 1% cream rinse or pyrethrins w piperonyl butoxide applied to the affected areas and washed off after 10mins

Scabies

Burrows in the skin

CONTAGIOUS;CLOSE CONTACT SPREAD

prominent feature is itching

H&P: intense noctural pruritus, linear burrows in webs of fingers, wrists.

Scabies tx

topical permethrin or oval ivermectin;treat household contacts

Scabies

Condyloma Acuminatum (genital warts)

STI due to HPV

H&P: flesh =-colored verrucous papules in anogenital region

Condyloma Acuminatum (genital warts) TX

topical agents (imiquimod,podophyllotoxin),cryotherapy, surgical removal.

Condyloma Acuminatum (genital warts)

Viral Exanthems

viral mediated skin eruptions

H&P: diffuse maculopapular rashes often w systemic symptoms.

Viral Exanthems TX

Supportive care

Erythema Infectiosum

parvovirus B19

viral infection causing immune mediated rash

Erythema Infectiosum TX

supportive, parvovirus IgM if needed

Erythema Infectiosum

Hand foot and mouth disease

primarily fecal oral

viral infection causing mucocutaneous lesions. enterovirus (coxsackie,type A16)

H&P: mild fever, uri symptoms, malaise, anorexia, decreased appetite

Hand foot and mouth disease TX

Supportive, antipyretics;hydration and pain control

Hand foot and mouth disease

Measles

part of the paramyxovirus family

transmission by respiratory droplets person to person, airborne.

H&P: fever, cough,coryza, conjunctivitis, Koplik spot, maculopapular rash

Measles 3C’s

Cough, Kariza, conjunctivitis

Measles TX

supportive; Vitamin A in severe pediatric cases; isolation.

Measles