Diagnosis

Eczema

Etiology

Cause

• Exogenous/enviromental factors:

  • Allergic contact dermatitis (metals, cosmetics, medicaments, rubber, plants, resins)

  • Non-allergic irritant contact dermatitis (80% of all contact dermatitis)

  • Photodermatitis

• Endogenous/genetic factors:

  • Atopic eczema (IgE-production as a response to common enviromental allergens assosiated with asthma, hay fever and food allergies)

  • Seborrhoeic eczema (assosiated with pityrosporum yeast causing greasy yellowish scales affecting hairy areas: scalp, face, presternum and intertriginous areas)

  • Discoid/Nummular eczema (suspected reaction to bacteria as the lesions often yield staphylococci on culture)

  • Pompholyx (unknown but provoked by heat and emotional upsets)

  • Venous stasis eczema (venous insufficiency and usually poor circulation cause eczematous rash on the lower legs)

  • Neurodermatitis/Lichen simplex (repetitive scratching)

Pathophysiology

1. Activated keratinocytes

2. Increased proliferation and increased cytokine secretion

3. Inflammation and scaling

Complications [us4]

• Bacterial super infections: Furuncles, impetigo, or cellulitis (S. aureus)

• Viral infections: Eczema herpeticum, keratoconjunctivitis, meningitis, encephalitis (herpes simplex)

• Eczema cosackium

Epidemiology

Prevalence per 100.000 [kbv][8av][upm][4pq]

Incidence per 100.000 [kbv][8av][upm][4pq]

Approach

• Biopsy

• Patch testing

Treatment

1. Nonmedical measures that may be helpful: [awb]

   • Soft clothing (cotton), avoid wool

   • Mild temperatures, particularly at night

   • Air humidifier (cool mist)

   • Washing clothes in a mild detergent, avoid bleach or fabric softener

   • Avoiding specific foods if there is concomitant food allergy

2. Mild-tomoderate atopic dermatitis: [rp2]

   • Emollients/moisturizers

   • Topical steroids

   • Topical calcineurin inhibitors

   • Crisaborole (topical Phosphodiesterase‐4 Inhibitor)

   • Tofacitinib (JAK-STAT inhibitor)

3. Moderate-to-severe atopic dermatitis: [rp2]

   • Phototherapy

   • Systemic corticosteroids (side effects)

   • Systemic immunosuppressants: Cyclosporine, Azathioprine, Methotrexate, and Mycophenolate mofetil

     • Risks and side-effects: Malignancy, nephrotoxicity, lymphopenia, hepatotoxicity, and infection

   • Biologic agents:

     • JAK-STAT inhibitors: Baricitinib, Upadacitinib, PF-04965842, ASN002, Ruxolitinib, and Delgocitinib

     • Phosphodiesterase‐4 Inhibitors: Roflumilast (topical), Apremilast (oral)

     • CRTH2 Antagonists: Fevipiprant/Timapiprant

     • TSLP and OX40 Inhibitors: GBR‐830, Tezepelumab

     • Therapeutic Aryl Hydrocarbon Receptor Modulating Agent: Tapinarof (topical)

     • IL‐4/IL‐13Inhibitors: Dupilumab, Pitrakinra, Tralokinumab, Lebrikizumab

     • IL‐5Inhibitors: Mepolizumab

     • IL‐22 Inhibitors: Fezakinumab

     • IL‐31/IL‐31RαInhibitors: BMS‐981164, Nemolizumab

     • Neurokinin‐1 Receptor Antagonists: Serlopitant, Tradipitant

     • Κ‐Opioid Receptor Agonists: Asimadoline

     • Histamine‐4 Receptor Antagonists: ZPL‐389

     • Immunoglobulin‐E (IgE) Inhibitors: Omalizumab, Ligelizumab

Differential diagnoses

Angioedema, Candidiasis, Contact dermatitis, Cutaneous T-cell lymphoma, Dermatitis herpetiformis, Drug eruptions, Erysipelas, Erythroderma, Ichthyosis vulgaris, Impetigo, Lichen planus, Lichen simplex chronicus, Molluscum contagiosum, Mycosis fungoides, Palmo+C790antar pustolosis, Photosensitivity, Pityriasis rosea, Pityriasis rubra pilaris, Pityriasis versicolor, Psoriasis, Scabies, Seborrheic dermatitis, Tinea corporis