L-32 Diagnosing Skin Conditions: Impetigo

• The lecture focuses on identifying and diagnosing common dermatological manifestations through clinical images and photo identification.

Case 1: Presentation and Diagnosis

• A 2-year-old male presents with a 1-week history of a rash around the nose.
• An older sister had similar symptoms two weeks prior.
• The rash is characterized by macules, papules, and vesicles on an erythematous base.
• Honey-colored crusting is noted.
• The diagnosis is likely nonbullous impetigo.
• The most common causative agent is Staphylococcus aureus, but Beta-hemolytic streptococci can also be responsible.

Case 1: Treatment

• Limited impetigo is treated with topical antimicrobial therapy.
• Mupirocin or retapamulin are first-line topical treatments.
• For excessive impetigo, treatment should be effective against S. aureus and streptococcal infections.
• Appropriate treatments include cephalexin and dicloxacillin.

Case 2: Presentation and Diagnosis

• A 66-year-old male presents with a painful rash on the right side of the chest, rated 9/10 in pain.
• The patient does not have fever, chills, or fatigue.
• Past medical history includes hypertension and hyperlipidemia.
• The patient is not vaccinated.
• The rash is unilateral, right-sided, vesicular, and on an erythematous base.
• The condition is diagnosed clinically, potentially with PCR testing at all stages of the lesions if atypical/hemorrhagic, especially if the patient is immunocompromised
• Reactivation of latent Varicella-Zoster virus (VZV) that had previously gained access to sensory ganglia during initial varicella (chickenpox) infection.

Case 2: Important Risk Factors and Treatment

• Age is the most important risk factor for developing herpes zoster, with a sharp increase in incidence around age 50.
• Immunocompromised are susceptible at any age.
• Ideally, patients should be treated within 72 hours of onset of lesions to lessen the severity and duration of pain associated with acute neuritis, promote rapid healing, prevent new lesion formation, decrease viral shedding, and prevent post-herpetic neuralgia.
• Antiviral therapy: Valacyclovir 1000 mg TID x 7 days, Famciclovir 500 mg TID x 7 days, and Acyclovir 800mg FIVE times a day x 7 days.
• The lesions are infectious until all lesions are crusted (re-epithelialized).
• Immunocompetent adults over 50 should receive recombinant zoster vaccine.

Case 3: Presentation and Diagnosis

• A 31-year-old female complains of worsening fatigue, multiple joint pain, and hair loss for 3 months, along with a new rash for 2 weeks.
• The patient has no significant past medical history.
• The patient recently went on a cruise and feels that the rash significantly worsened.
• The rash is flat, erythematous, non-blanching, and scaly in a butterfly shape involving the cheeks but sparing the nasolabial folds.
• Systemic Lupus Erythematosus (SLE) is high on the differential.
• Lab work includes CBC (may reveal anemia, thrombocytopenia), CMP (renal dysfunction), UA (hematuria, proteinuria), and SPEP (may show hypergammaglobulinemia).
• Labs that would support SLE if abnormal: Antinuclear Antibodies (ANA), Anti-double-stranded DNA (anti-ds DNA), Antiphospholipid antibodies, C3 & C4 levels, and ESR and/or CRP.

Case 3: Frequency of SLE Signs and Symptoms

• Fatigue: 50% at onset, 74-100% at any time.
• Fever: 36% at onset, 40-80+% at any time.
• Weight loss: 21% at onset, 44-60+% at any time.
• Arthritis or arthralgia: 62-67% at onset, 83-95% at any time.
• Skin: 73% at onset, 80-91% at any time.
• Butterfly rash: 28-38% at onset, 48-54% at any time.
• Photosensitivity: 29% at onset, 41-60% at any time.
• Mucous membrane lesion: 10-21% at onset, 27-52% at any time.
• Alopecia: 32% at onset, 18-71% at any time.
• Raynaud phenomenon: 17-33% at onset, 22-71% at any time.
• Purpura: 10% at onset, 15-34% at any time.
• Urticaria: 1% at onset, 4-8% at any time.

Case 4: Presentation and Diagnosis

• A 51-year-old male presents for an annual exam with no complaints.
• The patient takes no medications.
• The patient recently regained insurance after over 5 years without it.
• The patient reports weight gain and polyuria.
• Examination reveals a thick, leathery, hyperpigmented lesion on the posterior neck that is non-painful and cool to the touch.
• Tests that can narrow down the diagnosis include a Random Blood Sugar. A result of 358.
• The diagnosis is Acanthosis Nigricans.
• Thought to be due to insulin-like growth factor receptor-1, fibroblast growth factor receptor and epidermal growth factor receptor abnormalities.

Case 4: Related Conditions and Treatment

• Related conditions: Obesity, Disorders of insulin resistance (DM2), Genetic syndromes, Familial acanthosis nigricans, Malignancy, Drug reaction.
• Workup: HgbA1c, CMP, TSH.
• Treatment: Control DM through lifestyle changes (diet/exercise) and medications if needed.

Case 5: Presentation and Diagnosis

• A 34-year-old male presents with a rash for 3 weeks.
• The rash is non-painful, with no associated fevers, chills, bleeding, or pus drainage.
• The patient has not used new detergents or hygiene products.
• The patient is overall healthy and works as an accountant.
• The patient is single with multiple sex partners.
• The patient has no known sick contacts and has not traveled recently.
• The rash is diffuse, including the palms and soles, but sparing the face, and is red/brown maculopapular.
• The rash is non-tender, non-erythematous, and non-bleeding.
• The most likely diagnosis is secondary syphilis.

Case 5: Differential and Workup

• The differential diagnoses include Coxsackie virus (hand, foot & mouth), RMSF, Secondary Syphilis, Janeway lesions of bacterial endocarditis, Kawasaki's disease, measles, TSS, reactive arthritis, and Meningococcemia.
• The workup includes: Screening, non-treponemal testing via Rapid plasma reagin (RPR) and Confirmatory, treponemal testing via Fluorescent treponemal antibody absorption (FTA-ABS).
• Treatment consists of Penicillin G benzathine 2.4 million units IM once.

Case 6: Presentation and Diagnosis

• A 30-year-old female has an intensely pruritic rash on her elbows and knees for 3 months, with complaints of loose/pale stool.
• The patient has not traveled recently, stayed in hotels, or gone camping.
• The patient has positive ROS signs of abdominal bloating, gas, diarrhea, and weight loss.
• The patient has lost weight (150 lbs to 120 lbs in one year).
• The rash consists of multiple intensely pruritic papules and vesicles in grouped ("herpetiform") arrangements on the bilateral dorsal elbows and knees, without interdigit burrowing or jaundice.
• Given the patient's chief complaint, rash, and positive ROS, a systemic disease may be manifesting with a dermatologic complaint.
• The diagnosis is Dermatitis Herpetiformis due to Celiac Disease (gluten sensitivity).

Case 6: Diagnosis and Treatment

• Direct immunofluorescence (DIF) microscopy is the gold standard test for diagnosis, using a punch biopsy of lesion.
• The characteristic finding on DIF is the presence of granular deposits of IgA within the dermal papillae.
• Serology: Tissue transglutaminase (tTG)-IgA antibody is the single preferred test for detection of celiac disease in adults.
• Concurrently measure total IgA levels.
• The treatment consists of Gluten avoidance and Dapsone.

Case 7: Presentation and Diagnosis

• A 43-year-old female intermittently gets a non-painful rash on her face.
• The rash is worse during winter and summer but not as bad in spring and fall (Lives in NY).
• Spicy foods worsen the rash.
• Being out drinking with friends makes the rash worse.
• The rash description is centrofacial erythema, including the nasolabial folds and cheeks, with a few papules and scattered telangiectasias.
• The clinical diagnosis is Rosacea.

Case 7: Pathogenesis and Diagnosis Requirements

• Pathogenesis postulates include abnormalities in innate & adaptive immunity.
• Microorganisms such as Demodex mites, H. pylori, small intestinal bacterial overgrowth, S. epidermidis, and vascular hyperreactivity and UV light play a role.
• Rosacea diagnosis requires one diagnostic phenotype or two major phenotypes.
• Diagnostic phenotypes: Fixed centrofacial erythema in a characteristic pattern that may periodically intensify and Phymatous changes (thickened skin with enlarged pores and irregular surface nodularities).
• Major phenotypes: Papules and pustules, Flushing, Telangiectasia, and Ocular manifestations (e.g., lid margin telangiectases, interpalpebral conjunctival injection, spade-shaped infiltrates in the cornea, scleritis, sclerokeratitis).

Case 7: Treatment

• Avoidance of triggers/flushing is the first line measure (Extremes of temp, sunlight, spicy food, alcohol, exercise).
• Skin care is the first line measure. Recommendations are frequent skin moisturization with emollients, gentle skin cleansing, avoidance of irritating topical products, and sun protection.
• Second line interventions: Laser & intense pulsed light promotes vessel wall healing. Topical brimonidine has the strongest evidence for efficacy for persistent facial erythema through Vasoconstriction via alpha-2 adrenergic receptor.

Case 8: Presentation and Diagnosis

• A 30 year old male presenting for hair loss for the last 6 months.
• The hair loss is progressively worsening
• Monogamous with partner (recent STI testing negative).
• Notices significant hair loss throughout his scalp "in patches”.
• Examination reveals multiple patches of smooth, circular areas of complete hair loss w/o erythema, scaling, pus drainage.
• Admits to fatigue and weight gain, denies hair pulling, anxiety, and scalp picking.
• Mainly history- assess the onset and duration of hair loss as well as associated symptoms.
• The diagnosis is Alopecia Areata, which presents as sudden, asymptomatic hair loss.

Case 8: Examination and Thyroid Studies

• Physical examination should include careful examination of the hair, scalp, and other hair-bearing areas to assess the distribution and extent of hair loss and to detect findings suggestive of other hair or scalp diseases.
• Smooth, round, or irregular areas of nonscarring hair loss are typical of alopecia areata.
• Close visual inspection may reveal exclamation point hairs, a pathognomonic finding of alopecia areata.
• Because of the association between alopecia areata and autoimmune thyroid disease and the relatively high frequency of thyroid disease in the general population, perform thyroid studies - screen adults and children with alopecia areata for this disorder.