Pustular psoriasis in Child
The etiology of pustular psoriasis is incompletely understood, but cases have been associated with hypocalcemia, infection (Trichophyton rubrum, cytomegalovirus, Streptococcus spp., varicella-zoster, and Epstein-Barr virus), a rapid withdrawal of corticosteroids, pregnancy, medications (salicylates, lithium, potassium iodine, trazodone, penicillin, interferon, and hydroxychloroquine), and topical irritants such as tar and anthralin. While tumor necrosis factor (TNF)-alpha antagonists such as infliximab and adalimumab are used to treat pustular psoriasis, they have also been reported paradoxically to induce it. Only a small number of children with pustular psoriasis have a preceding history of plaque-type psoriasis.
There are 4 subtypes of pustular psoriasis:
- von Zumbusch type: acute onset of generalized erythema and pustules with systemic manifestations including fever, skin tenderness, malaise, arthralgias, headache, and nausea. After several days, the pustules resolve to become confluent, scaling plaques.
- Exanthematic type: acute onset of small pustules that are triggered by an infection or a drug. This subtype usually lacks systemic symptoms.
- Annular subtype: erythematous, annular lesions that have pustules at the advancing edge of a lesion and is associated with fever, malaise, and other systemic manifestations.
- Localized pattern: pustules appear in existing psoriatic plaques. This can be seen in active plaques. Palmoplantar psoriasis is the most common form of localized pustular psoriasis.
Pustular psoriasis in children often has a more benign course than in adults, and children have a higher rate of spontaneous remission of generalized pustular psoriasis. Pediatric pustular psoriasis may be part of SAPHO syndrome (synovitis, acne, psoriasis / palmoplantar pustulosis, hyperostosis, osteitis).
For more information on generalized pustular psoriasis, see OMIM.
L40.1 – Generalized pustular psoriasis
200973000 – Pustular psoriasis
- Acute generalized exanthematous pustulosis (AGEP) – Clinically indistinguishable from pustular psoriasis. Time of onset and a drug history may help differentiate AGEP from pustular psoriasis. Antibiotics are the likely causative agents in AGEP. Histology can also help differentiate between the two. Also look for high fever, edema of the face, pustular eruption that occurs shortly after drug administration (fewer than 2 days), marked serum leukocytosis with neutrophilia, and associated petechiae, purpura, and vesicles in AGEP.
- Toxic epidermal necrolysis
- Drug reaction with eosinophilia and systemic symptoms (DRESS) – Look for marked eosinophilia, visceral involvement (most commonly hepatitis), less acute onset, facial edema, and atypical lymphocytosis.
- Subcorneal pustular dermatosis (Sneddon-Wilkinson disease) – Associated with IgA paraproteinemia and is very responsive to dapsone. Pustular psoriasis is not responsive to dapsone and does not have an IgA paraproteinemia.
- Deficiency in the interleukin-36 receptor antagonist (DITRA)
- Keratoderma blennorrhagicum seen in reactive arthritis disease – Look for characteristic associated findings including urethritis, arthritis, and ocular findings.
- Dyshidrotic eczema – Extremely pruritic, restricted to hands and feet, look for deep-seated vesicles that look like tapioca pudding.
- Erythema annulare centrifugum – To be considered when annular-type psoriasis is observed. No associated systemic findings. Individual lesions can last for months.
- Disseminated herpes simplex