Subcorneal Pustular Dermatosis Clinical Presentation

Updated: Jun 11, 2021
  • Author: Lidija Kandolf Sekulovic, MD, PhD; Chief Editor: Dirk M Elston, MD  more...
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Subcorneal pustular dermatosis (SPD) is a benign, chronic, vesiculopustular eruption, usually affecting adults, although childhood cases have also been described. [2, 3, 4, 5] Patients typically present with a history of a relapsing pustular eruption involving the flexural areas of the trunk and proximal extremities. Individual pustular lesions arise within a few hours. Pruritus and irritation can occur but are not usually prominent symptoms. Systemic and toxic symptoms are not associated with acute episodes. However, malaise, fever, arthralgias, abnormalities of hepatic enzymes, and sclerosing glomerulonephritis have been reported in several cases. [25] Patients typically do not have any symptoms or signs of mucosal involvement.

Patients may present with histories notable for monoclonal gammopathies (IgA more often than immunoglobulin G) [8, 9] ; lymphoproliferative disorders (especially multiple myeloma) [11] ; pyoderma gangrenosum [10, 26] ;  and other inflammatory diseases such as rheumatoid arthritis, [12, 13, 27] ,systemic lupus erythematosus, [28] Sjögren syndrome, [29] diffuse scleroderma, [30] ulcerative colitis, [31] and Crohn disease. [14, 15] These conditions are well-recognized associations with subcorneal pustular dermatosis (developing both before and after the diagnosis of subcorneal pustular dermatosis). Further associations were found with other dermatoses characterized by skin infiltration with neutrophils, such as pyoderma gangrenosum and SAPHO (synovitis, acne, pustulosis, osteitis) syndrome. [32] Other anecdotally associated conditions include aplastic anemia, [33]  Mycoplasma pneumoniae infection, [34, 35, 36]  Coccidioides immitis infection, [37]  hyperthyroidism, [38] APUDoma (amine precursor uptake and decarboxylation cell–derived tumor), [39] and thymoma. [40]

Patients should be queried about a personal and family history of psoriasis, because differentiating subcorneal pustular dermatosis from pustular psoriasis can be difficult. Similarly, patients should be questioned about recent drug exposure because acute generalized exanthematous pustulosis is also in the differential diagnosis. [41]


Physical Examination

The primary lesions are flaccid pustules, measuring several millimeters in diameter, on normal or mildly erythematous skin. The classic lesion has been described as a "half-and-half" blister, in which purulent fluid accumulates in the lower half of the blister. New eruptions of pustules have the tendency to coalesce and often form annular, circinate, and bizarre serpiginous patterns.

See the images below.

Circinate plaques and pustules on nonerythematous Circinate plaques and pustules on nonerythematous base in a patient with subcorneal pustular dermatosis.
Subcorneal pustular dermatosis with numerous pustu Subcorneal pustular dermatosis with numerous pustules on erythematous base.

This tends to occur symmetrically, affecting axillae, groin, abdomen, submammary areas, and the flexor side of the limbs. There are no differences in clinical features and prognosis of the disease between children and adults. [23, 24, 42] Palmar, plantar, face, and mucous membrane involvement is unusual, but is described in individual case reports. [43, 44]

The pustules can be isolated or grouped and tend to coalesce and form annular, circinate, or serpiginous patterns. The pustules are superficial and rupture easily, resulting in a superficial crust.

Mild hyperpigmentation often remains after pustular lesions have resolved.