Common Skin Conditions: Diagnosis and Treatment

Posted on Dec 3, 2024 in Medicine & Health

Dermatitis Herpetiformis

Symptoms (Sx)

  • Chronic itching and vascular changes

Pathophysiology (Px)

  • IgA antibodies against transglutaminase
  • Granular IgA deposits in the dermis
  • Gluten sensitivity
  • Association with HLA-DQ2/8

Clinical Features (CF)

  • Small vesicles, red macules, erosions, crusts
  • Association with celiac disease

Diagnosis (Dx)

  • Clinical features, cytology, histopathology (subepiderminal blisters rich in eosinophils)

Treatment (Tx)

  • Gluten-free diet
  • Dapsone (15-300mg)
  • Wound care

Condylomata Acuminata

General (Gx)

  • Most common sexually transmitted disease (STD)

Pathophysiology (Px)

  • Human papillomavirus (HPV)

Clinical Features (CF)

  • Incubation period: 4-6 months
  • White papules in the genital area
  • Growth and spread of lesions

Diagnosis (Dx)

  • 5% acetic acid application for visualization
  • Cervical examination (women)

Treatment (Tx)

  • Cryotherapy
  • Trichloroacetic acid (TCA)
  • Podophyllotoxin 5%
  • Imiquimod 5% cream (6 weeks)

Trichomoniasis

Epidemiology (Epi)

  • More common in women than men

Clinical Features (CF)

  • Urethritis in men
  • Vaginitis in women
  • Pain during sexual intercourse and urination
  • Yellow-green, “fishy” vaginal discharge

Diagnosis (Dx)

  • Saline microscopy
  • Culture
  • Nucleic acid amplification tests (NAATs)

Treatment (Tx)

  • Metronidazole

Prevention (Pr X)

  • Safe sex practices

Lichen Planus

Idiopathic inflammatory disease affecting skin, hair, nails, and mucous membranes.

Pathophysiology

  • T-cell and cytotoxic T lymphocyte (CTL) infiltration leading to increased interferon-gamma (IFN-γ) and tumor necrosis factor (TNF) release
  • Association with HLA-DR8
  • Keratinocyte adhesion dysfunction leading to basal cell damage and reactive hyperkeratosis

Clinical Features

  • Commonly affects wrists, forearms
  • Subjective pruritus
  • Objective: polygonal, flat-topped papules with fine scales

Diagnosis

  • Clinical features
  • Histology: irregular acanthosis, colloid bodies in the epidermis

Treatment

  • Topical corticosteroids
  • Systemic corticosteroids
  • PUVA (psoralen + UVA)

Scabies

Etiology

Sarcoptes scabiei hominis

Clinical Features

Pediculosis Capitis (Head Lice)

  • Itching
  • Lichenification
  • Crusting
  • Excoriation

Pediculosis Pubis (Pubic Lice)

Similar to head lice.

Pediculosis Corporis (Body Lice)

  • Sites: wrists, elbows, armpits
  • Pruritus, especially at night
  • Papular rash
  • Tiny burrows
  • Secondary exanthema (eczema, impetigo, crusted scabies)

Diagnosis

  • Patient history
  • Skin scraping
  • Microscopy
  • Histopathology: female tick on the stratum corneum

Treatment

  • Shaving affected area
  • Hot air treatment
  • Silicone lotions
  • Benzyl benzoate
  • Miticides (permethrin, benzyl benzoate, sulfur)

Prophylaxis

  • Treatment of close contacts
  • Washing clothes and bedding
  • Eliminating contact with infested items

Herpes Simplex Virus (HSV) and Varicella-Zoster Virus (VZV)

HSV-1 & HSV-2VZV (Chickenpox in children, Shingles in adults)

Clinical Features

  • Orofacial lesions
  • Herpetic keratitis
  • Herpetic encephalitis
  • Genital herpes
  • Herpetic gingivostomatitis
  • Herpetic eczema (disseminated HSV in atopic dermatitis)
  • Systemic symptoms: fever, malaise

Clinical Features

  • Pain, itching, paresthesia in affected dermatome
  • Primary lesions: vesicles with clear serous fluid, often umbilicated
  • Secondary lesions: papules, hypo/hyperpigmented macules
  • Fever, malaise

Diagnosis

  • Clinical features
  • Viral culture
  • Electron microscopy
  • Serology
  • PCR

Diagnosis

  • Clinical features
  • Culture
  • Tzanck smear
  • PCR
  • Direct immunofluorescence (DIF)

Treatment

  • Antivirals (acyclovir, valacyclovir)
  • Drying agents (zinc oxide lotion)
  • Vaccination against HSV-2 (women)

Treatment

  • Self-limiting in many cases
  • NSAIDs for pain
  • Antiseptics for skin lesions
  • Antivirals (famciclovir, acyclovir, valacyclovir)

Impetigo, Ecthyma, Staphylococcal Scalded Skin Syndrome (SSSS)

ImpetigoEcthymaSSSS

Superficial skin infection affecting the epidermis.

Pathophysiology

  • Streptococcus pyogenes, Staphylococcus aureus

Clinical Features

  • Commonly affects head, neck, palms
  • Lesions: macules, vesicles, erosions, blisters

Infection of deeper skin layers.

Pathophysiology

  • Streptococcus pyogenes, Staphylococcus aureus

Clinical Features

  • Commonly affects feet, tibia, femur
  • Painful ulcers with crusts
  • Altered healing, scarring

Toxin-mediated epidermal damage, mostly in infants.

Pathophysiology

  • Staphylococcus aureus

Clinical Features

  • Commonly affects oral mucosa, mouth, eyes, ears
  • Lesions: blisters, erosions, skin detachment, wrinkles

Diagnosis

  • Gram stain
  • Culture
  • Blood test (leukocytosis)
  • Antistreptolysin O (ASO) titer

Treatment

  • Systemic antibiotics (penicillin, cephalosporin, oxacillin)
  • Topical antibiotic ointment

Folliculitis, Furuncle, Carbuncle

FolliculitisFuruncleCarbuncle

General

  • Infection of the hair follicle

Pathophysiology

  • Staphylococcus aureus, Pseudomonas aeruginosa, HSV-1

Clinical Features

  • Locations: inguinal, gluteal, axillary regions
  • Lesions: small, red rings around hair follicles, yellow/white pustules

General

  • Infection of the hair follicle and surrounding tissue

Pathophysiology

  • Staphylococcus aureus

Clinical Features

  • Locations: similar to folliculitis
  • Lesions: red, painful nodules, necrotic mass, yellow pus, may progress to abscess

General

  • Infection of several hair follicles and surrounding tissue

Pathophysiology

  • Staphylococcus aureus

Clinical Features

  • Locations: similar to folliculitis
  • Lesions: red, painful nodules, necrotic mass, yellow pus, may progress to abscess

Diagnosis

  • Gram stain
  • Microscopy
  • Culture

Treatment

  • Topical antimicrobials

Vaccinations

  • Diphtheria, Tetanus, Pertussis (DTaP): Td (toxoid) 0.5ml IM at 0, 2, 4, 6, 15-18 months, and 4-6 years; booster every 10 years. Tetanus immune globulin (TIG) for large wounds, Td for large and small wounds.
  • Varicella: 0.5ml SC, two doses 4-8 weeks apart.
  • Measles, Mumps, Rubella (MMR): Live attenuated vaccine, 0.5ml SC, two doses.
  • Influenza: Inactivated vaccine, 0.5ml IM annually.
  • Pneumococcal: 0.5ml IM, booster after 5 years.
  • Hepatitis B: 1ml IM in deltoid at 0, 1, and 6 months.

Genital Herpes

General

  • HSV-2
  • Sexually transmitted infection

Clinical Features

  • Malaise, fever, fatigue
  • Painful urination
  • Bilateral lymphadenopathy
  • Lesions: disseminated, rapidly eroding vesicles, painful ulcers

Diagnosis

  • Serology (most accurate)
  • Clinical presentation
  • Tzanck smear
  • PCR
  • Culture

Treatment

  • Antiviral medications
  • Drying measures (zinc oxide)
  • Vaccination against HSV-2