Pathological Case of the Month

Figure 1 and Figure 2. Red papules, varicelliform vesicles, and pustules; some evolved into crusted hemorrhagic lesions and others into ulceronecrotic lesions with a sanguineous gray fibrinous exudate and an erythematous halo.

Figure 3. Focal spongiosis and edema accompanied by vacuolar alteration and neutrophils; necrotic keratinocytes were evident in the epidermis. The corneum layer was orthokeratotic and compact (hematoxylin-eosin, original magnification ×250).

Pityriasis lichenoides (PL) and varioliformis acuta was described in 1916 by Mucha¹ and later in 1925 by Haberman² and is also called Mucha-Haberman disease (M-HD). It is the acute form of PL, an uncommon cutaneous disease mainly occurring in young adult men. Mucha-Haberman disease is not rare in children: 18.6% of the overall population in the series by Romanì et al³ were children. In children, M-HD may be only a particular form of PL; in the largest series reported in the literature,^4-6 most patients had both acute and chronic lesions of PL simultaneously and a chronic course with some acute relapses. The disease M-HD is characterized by the abrupt onset of papulovesicles that evolve into necrotic lesions especially on the trunk (anterior area) and the arms (proximal part and flexor surfaces). Sometimes the eruption involves the entire body surface. Mucous membrane involvement is rare. The lesions are reddish brown papules with central vesiculation and sometimes hemorrhagic necrosis. Usually, the lesions evolve into varioliform scars which leave hypohyperpigmentation.

The eruption is accompanied by only minimal general symptoms. Elevated temperature is a rare complication of M-HD; when fever is present, it is very high (up to 40°C-41°C) and frequently associated with asthenia, severe malaise, and intense myalgias, and the cutaneous eruptions are more severe with painful and large necrotic ulcers. This severe variety first reported by Degos et al⁷ in 1966 occurs both in adults and children but it appears more frequent in childhood. In children some mucosal lesions have been observed. A central nervous system involvement is described with stupor, agitation, and neuropsychiatric alterations. Arthritis is a common associated complication.

In patients with febrile M-HD, an elevated erythrocyte sedimentation rate, C-reactive protein level, and leukocyte count has been found; in a few cases, antistreptolysin A antibodies and eosinophils were increased. Despite bacteria being isolated from skin cultures, this is not considered the etiological agent of the disease. The histopathological findings of leukocytoclastic vasculitis in the acute variety of M-HD and the occasional presence of circulating immune complexes suggest that the cutaneous lesions are the result of the vascular deposition of an infectious organism, which is the trigger factor of a reaction of hypersensitivity. Other reports suggest an association with a hyperimmune state in M-HD and febrile M-HD.

The course of M-HD is usually self-limited to a few weeks or months, occasionally changing into a chronic course with exacerbations and remissions. The febrile variant may be prolonged for many months and may lead to death. Treatment with antibiotics has been recommended for control of the superinfection. Many other therapies have been proposed; however, no treatment seems completely effective in MH-D. The main treatments proposed in children with M-HD are erythromycin with a 1- to 5-month course, psoralen UV-A light treatment or only UV light treatment, and natural sunlight exposition, which all have had good responses in most patients, but the evaluation of their efficacy is difficult because of the tendency of PL to follow a self-limited natural clinical course.

Differential diagnosis between M-HD and other papular or papulovesicular and crusted eruptions of childhood (in particular Crostis syndrome, varicella, and erythema multiformse) may be difficult, and the correct diagnosis is sometimes obtained only by histopathologic analysis. In addition, the transformation into cutaneous T-cell lymphoma observed in sporadic reports of PL⁸ and the clinical and histopathological similarities between M-HD and lymphomatoid papulosis is still a matter of debate.

Accepted for publication February 1, 1999.

Reprints: Giampaolo Ricci, MD, Department of Pediatrics, University of Bologna, Via Massarenti 11, 40139 Bologna, Italy.