Nonbacterial pus-forming diseases of the skin Robert Jackson,* m.d., f.r.c.p[c], Ottawa, Ont. Summary: The formation of pus as a Things are not always what they seem Fungus result of an inflammatory response Phaedrus to a bacterial infection is well known. North American blastomycosis, so- Not so well appreciated, however, The purpose of this article is to clarify called deep mycosis, can present with a is the fact that many other nonbacterial the clinical significance of the forma¬ verrucous proliferating and papilloma- agents such as certain fungi, viruses tion of pus in various skin diseases. tous plaque in which can be seen, par- and parasites may provoke pus Usually the presence of pus in or on formation in the skin. Also heat, the skin indicates a bacterial infection. Table I.Causes of nonbacterial topical applications, systemically However, by no means is this always pus-forming skin diseases administered drugs and some injected true. From a diagnostic and therapeutic Fungus materials can do likewise. Numerous point of view it is important that physi¬ skin diseases of unknown etiology cians be aware of the nonbacterial such as pustular acne vulgaris, causes of pus-forming skin diseases. North American blastomycosis pustular psoriasis and pustular A few definitions are required. Pus dermatitis herpetiformis can have is a yellowish [green]-white, opaque, lymphangitic sporotrichosis bacteriologically sterile pustules. The somewhat viscid matter (S.O.E.D.). Pus- cervicofacial actinomycosis importance of considering nonbacterial forming diseases are those in which Intermediate causes of pus-forming conditions of pus can be seen macroscopicaily. Pus- the skin is obvious from a diagnostic forming bacteria are those that nor- jntertrigmous candidiasis and therapeutic point of view. mally, frequently or usually cause Superficial suppuration. R6sume: Dermatoses purulentes As has been pointed out in Topley suppurative ringworm (kerion) d'origine nonbacte'rienne and Wilson's textbook,1 the separation Virus of bacteria into pyogenic and nonpyo- On connait bien la formation de genic groups is quite arbitrary. For Herpes zoster pus comme traduction d'une reaction example, the characteristic reaction of Variceiia inflammatoire a une infection the tubercle bacillus (a nonpyogenic Variola bacterienne. Moins bien connu par organism) is usually a nonsuppurative contre est le fait que de nombreux granuloma. However, in the pleural ca- Herpes simplex agents nonbacteriens, certains fongus, vity, meninges and urinary bladder this Vaccinia virus et parasites notamment, peuvent organism may cause the formation of provoquer la formation de pus au pus and hence may be called a pyogenic Protozoa and arthropods niveau de la De la chaleur, peau. m§me, organism. Many other examples could Amebiasis les applications locales, des be given. In fact, there are few bac¬ medicaments administres par voie terial species that are not pyogenic, Myiasis generale et certaines substances in the sense that their presence may injectees peuvent avoir le meme effet. call forth the formation of pus under Physical De nombreuses dermatoses d'etiologie certain circumstances. Miliaria pustulosa inconnue, comme I'acne pustuleuse How can one account for the pres¬ vulgaire, le psoriasis pustuleux et la ence of pus in those diseases presum- Systemic drugs dermatite herpetiforme pustuleuse ably not caused by pus-forming bac¬ lododerma and bromoderma peuvent etre constituees de pustules teria? There are three possible reasons: qui, du point de vue bacteriologique, (1) pyogenic organisms are present but Topical applications sont steriles. De sorte, qu'au double are not cultured owing to faulty tech- Tar foliiculitis point de vue diagnostique et nique; (2) pyogenic organisms are pres¬ therapeutique il est important de ent as saprophytes or as a superinfec- Sterile pustular patch tests considerer les or there be a pathologies purulentes tion; (3) may pustular material qui ont des etiologies nonbact6riennes. tissue response to fungi or viruses, or Injected to physical causes, systemic drugs, to¬ Foreign body granuloma pical applications or injected material. There are also many miscellaneous skin Miscellaneous diseases in which sterile pus formation Pustular acne vulgaris occurs. The remainder of this paper Pustular psoriasis talks about reason (3) in detail. The number of skin diseases in which localized (palms and soles) nonbacterial pus formation can be generalized found is legion and Table I is a partial outline and from each Sneddon's subcomeal pustulosis To be presented to the Ottawa Bacteriology Club listing. Examples November 12, 1974 group of etiologic agents follow, with Pustular dermatitis herpetiformis .Assistant professor of medicine fdermatology), particular attention to those diseases Furunculoid and acneiform lesions in ulcerative University of Ottawa; dermatologist, Ottawa that are not too uncommon and that Civic Hospital colitis and Behget's disease not are as Reprint requests to: Dr. R. Jackson, Suite S08, infrequently diagnosed being Ulcers 1081 Carling Ave., Ottawa, Ont. K1Y 4G2 primarily due to the action of bacteria. CMA JOURNAL/OCTOBER 19, 1974/VOL. 111 801 ticularly at the border, numerous pin- Protozoa and arthropods frequently give rise to a sterile acnei- head-sized pustules (Fig. 1). In the form located Cutaneous amebiasis pustular eruption, usually pustules, on direct smear or in histologic presents large on the face and upper trunk. By group- sections, the budding organisms of deep ulcers with a dull red base, glisten- ing and extension of these pustular Blastomyces dermatitidis can be found. ing and dotted with islands of epithe- lesions more complex papillomatous, Lymphangitic sporotrichosis (Fig. 2) lium, shreds of pus and necrotic ma¬ proliferating and fungating plaques and presents as a nonhealing, centrally ul- terial. Pressure on the border will nodules may be produced; all of these cause to exude. In this cerative papulonodule in a linear ar- pus pus Enta- complex types have a pustular element moeba can rangement following the cutaneous histolytica be found. and the overall clinical picture may lymphatics, particularly of the forearm. Cutaneous myiasis is the term used closely resemble North American blas¬ Purulent material from the central ulcer to describe the lesion produced by any tomycosis. When the drug is stopped will contain Sporothrix schenckii. In- fly larva under the skin. At times it the lesions disappear. terestingly, it is usually treated by the produces a raised, pointed, indurated, oral administration of a potassium erythematous lesion with a small cen¬ iodide solution which itself may rarely tral sinus from which a small amount cause a pustular eruption. of pus can be expressed. On more Candidal infections can be both su- pressure, however, several fly larvae can be extruded. perficial and deep and are therefore Furuncular myiasis classified as intermediate In- may be due to many types of flies, for mycoses. and tertriginous candidiasis presents with a example Wohlfahrtia vigiP Hypo- large, well-defined, bright red, exuding, derma bovis. irregular patch (Fig. 3). The borders of this lesion are scalloped and ragged Physical because the epidermis is exfoliated. Satellite 1- to 2-mm vesiculopustules Miliaria rubra (or prickly heat) is an on an erythematous base are seen, de- erythematous papulovesicular eruption encountered in situations ex- creasing in number and size as one provoking cessive the use of moves from the central patch to the sweating, including periphery. A small bead of seropurulent occlusive substances such as pliable material can be found in each vesiculo- transparent plastic film. Sometimes sterile seen pustule. Smear and culture of this pus pustules5 may be amid the will show Candida albicans. vesicles. These pustules are not folli- cular and it is important to Suppurative ringworm, an example distinguish of the so-called is miliaria pustulosa (Fig. 9) from bac¬ superficial mycoses, terial folliculitis, for the treatment is a pustular folliculitis due to numerous quite different. fungi, for example Trichophyton verru- cosum. The source is usually cattle. It is manifest by circular boggy swellings, Systemic drugs angry red in colour and dotted with Bromine and iodine and abscesses. Birt and Wilt2 compounds perifollicular iodides or bromides not in- took specimens for bacterial culture containing from 10 cases of suppurative ringworm; bacteria were not recovered from any of the lesions. FIG. 2.Chancre of lymphangitic sporotrichosis on finger. Virus Many disseminated viral diseases such as herpes zoster (Fig. 4), varicella (Fig. 5) and variola have a sterile pustular phase in their evolution. In most cases, however, the diagnosis is easily made and confusion with a bac¬ terial disease is unlikely. Primary herpes simplex of the finger may simulate a coccal infection in that there may be swelling, redness and tenderness, with regional lymphangitis and lymphadenitis (Fig. 6). The basic lesion, however, is a clear vesicle and no pus is present. Gavelin and Knight3 report considerable surgical intervention and four negative bacterial smears and cultures before a diagnosis of herpes whitlow was made in a nurse working on a neurosurgical ward. Recurrent herpes simplex may have a pustular phase (Fig. 7). One of the stages of of vaccinia FIG. 3.Intertriginous candidiasis. Note development primary (Fig. FIG. 1.North American blastomycosis satellite lesion on abdomen and inner 8) may be pus formation. on dorsum of hand.