Story of a Scalp Studded with (Crateriform) Scars

A 24-year-old Indian Hindu male shaved the hair off his head recently, while participating in a family ritual. He noticed that a major part of his scalp was covered with scars of varying sizes. The patient could not recollect the history of any skin condition, including pain and itching on his scalp in the past, which might have caused such scarring. Although asymptomatic at present, the lesions triggered significant feelings of anxiety to the patient.

On cutaneous examination, innumerous reddish-brown, pinhead to match-head sized crateriform scars were noted all over the scalp (Fig. 1a). Discrete, erythematous, non-tender papules and papulopustular lesions were interspersed among the crateriform scars, with umbilicated summits in a few. Most follicular units contained 2–3 hairs, while a small proportion had 4–5 hairs in the absence of hair tufting. Mild seborrhea was present (Fig. 1b). Besides scalp, few crateriform scars were also noted in the supraciliary region and over the bridge of nose. Rest of the skin was unremarkable.

Fig. 1.

a Crateriform scars, papules, and papulopustular lesions over the scalp (scar-studded appearance). b Close view of the reddish-brown crateriform scars, with mild seborrhea.

The general physical examination and systemic examination were normal. Complete blood count, C-reactive protein, and routine blood chemistry were within normal limits. Microbiological examination from pustule was unremarkable. A 5-mm punch biopsy from the scalp was performed, which revealed dilated follicular sheaths filled with necrotic keratinocytes and inflammatory debris. Intense perifollicular inflammation and follicular destruction were observed, leaving behind few remnant hair shafts (Fig. 2a, b).

Fig. 2.

a Photomicrograph showing intense perifollicular inflammation (black arrow) and destruction of hair follicle with remnant hair shaft (blue arrow) (hematoxylin and eosin stained, ×10). b Photomicrograph showing follicular destruction and remnant hair shaft (red arrow) (hematoxylin and eosin stained, ×40).

What Is Your Diagnosis?

Diagnosis: Acne Necrotica “Varioliformis” (Necrotizing Lymphocytic Folliculitis)

Acne necrotica was initially described by Bazin in 1851. Rarely mentioned in recent texts, this entity was acknowledged by various terms in the older literature like acne frontalis, acne varioliformis, acne pilaris, necrotizing lymphocytic folliculitis, acne atrophica, and pustular perifolliculitis [1, 2]. It is an uncommon skin condition, which chiefly affects women in their early to late adulthood [2]. It is characterized by recurrent crops of tender papules and papulonodules, which rapidly necrotize to leave behind superficial varioliform scars of variable degrees. The lesions are generally limited to nose, forehead, and anterior scalp, although anterior chest and interscapular areas can also be involved in severe cases [3, 4]. It has been proposed that acne necrotica varioliformis represents acquired sensitivity to staphylococcal toxin, with the subsequent formation of necrotic plugs and scars, but recent work in this field is lacking [5]. Further, it was hypothesized that lesions of acne necrotica begin as lymphocytic folliculitis, which are then triggered by Propionibacterium acnes [6].

A milder variant, acne necrotica “miliaris” was recognized by Sabouraud in 1928. In contrast to the classical variant, it is nonscarring, confined to the scalp, and characterized by extremely itchy vesiculopustular lesions. Recently, head and neck micropapular and disseminate variants have also been described [3].

Histopathologically, early lesions of acne necrotica are characterized by superficial perifollicular lymphohistiocytic infiltrate, which is seldom captured due to missed diagnosis in the early phase. As necrosis develops, histopathology reveals keratinocyte necrosis in the outer root sheath of the pilosebaceous unit, and neutrophilic infiltration in the adjacent epidermis and dermis. Established necrotized lesions show heavy non-specific perifollicular inflammation and remnant hair shafts [3, 7, 8], similar to the present case. Histopathology helped in ruling out the differential diagnoses such as gram-negative folliculitis, folliculitis decalvans, lupus miliaris disseminates faciei, pityriasis lichenoides et varioliformis acuta, and dermatitis artefacta.

Topical benzoyl peroxide, tretinoin, corticosteroids, disinfectants, topical and oral antibiotics, and oral isotretinoin have been tried in the past with limited benefits. Systemic corticosteroids attenuate the inflammation, but are not curative [1, 2, 9]. Recurrence of lesions is common on decreasing the dose or on discontinuation of the treatment. The review of the literature on acne necrotica, along with the various therapeutic regimens described in the literature is summarized in Table 1 [3, 5, 6, 7, 10, 11, 12]. Doxycycline 100 mg oral daily dose was prescribed to the present patient, and some improvement in papular and papulopustular lesions was seen in 4 weeks.

Table 1.

Summary of literature review on acne necrotica

Author, year, and type of publication	Age and sex of patients	Duration	Clinical findings	Distribution of lesions	Symptoms, course, and seasonal variations	Microbiological examination	Diagnosis (term used by author)	Treatment	Response to treatment
Stritzler et al. [5] (case report)	41 years, male	2 years	Reddish-brown, necrotic papules, vesicles, papulovesicular lesions with depressed summits, and crateriform scars	Scalp, hairline, bearded-region, and interscapular area	Intense pruritus, little seborrhea; remissions, and exacerbations at irregular intervals	Staphylococcus aureus	Acne necrotica (acne varioliformis)	X-ray therapy; mercury-bichloride lotion in 50% alcohol; potassium arsenite solution, 5 drops 3 times daily for 1 month; ultraviolet radiation; 3 injections of 12 mg oxophenarsine hydrochloride; Staphylococcus toxoid, 1 injection weekly (10 injections); autogenous vaccine of a nonhemolytic, coagulase-positive Staphylococcus aureus; tyrothricin ointment and wet dressings; penicillin ointment, 500 units per gram in a water-miscible base	Short remission
								Penicillin, 100,000 units in solvecillin (a penicillin vehicle) daily for six days	Sustained remission for 5 weeks
	27 years, female	Several years	Crateriform scars, crusted papules, removal of which left depressed scars or ulcers	Margins of the scalp, forehead, nose, and eyebrows	Mild seborrhea, acne; periodic remission and relapse	Hemolytic Staphylococcus aureus on culture (sensitive to streptomycin)	Acne necrotica (acne varioliformis)	300,000 units of penicillin in oil twice weekly; streptomycin 1 g daily for five days	Dramatic improvement, but flared-up on decreasing dose or discontinuing treatment
								Sulfapyridine, 1 g three times a day	Remission, but treatment was stopped due to drug-induced rash
								600,000 units of penicillin procaine once weekly	Remission
Hunter et al. [10] (correspondence)	52 years, male	1 week	Intake of phenylbutazone 200 mg, followed by excoriated papules and varioliform scars after 2 weeks	Forehead near hairline	Irritation; lesions healed on stopping phenylbutazone reappeared on restarting the same	Not done	Phenylbutazone induced acne necrotica	Sulfur-salicylic acid 2% ointment	Complete remission
Kossard et al. [7] (case series)	71 years, female	3 years	Umbilicated papules and varioliform scars	Face, scalp, and chest	Pruritus, tenderness; appeared as crops; more symptomatic during summers	Not done	Acne necrotica (varioliformis) or necrotizing lymphocytic folliculitis	Tetracycline 250 mg twice a day	Marked reduction in the number of fresh lesions
	45 years, female	29 years	Crusted follicular papules, varioliform, and cribriform scars	Face, anterior scalp, chest, and periumbilical area	Pruritus, tenderness; lesions increased during summers	Not done	Acne necrotica (varioliformis) or necrotizing lymphocytic folliculitis	Doxycycline 50 mg per day; betamethasone dipropionate cream	Reduction in lesions; relapse on stopping medicines
	69 years, male	40 years	Crusted papules, varioliform, and cribriform scars	Face, anterior scalp, back of neck, and central chest	Intermittent crops; reduced clinical activity during winters	Not done	Acne necrotica (varioliformis) or necrotizing lymphocytic folliculitis	Fluorinated steroid creams, doxycycline 50 mg/day	Initial improvement
								13-cis-retinoic acid 30 mg per day	Sustained remission (at 3 months follow-up)
	53 years, male	18 years	Umbilicated papules, varioliform scars	Scalp, eyebrows, beard area, and chest	Pruritus, tenderness; continuous progression	Not done	Acne necrotica (varioliformis) or necrotizing lymphocytic folliculitis	Doxycycline 50 mg/day; 1% salicylic acid and 1% precipitated sulfur in aqueous cream	Marked improvement over 4 months period
Fisher et al. [6] (correspondence)	13 patients (8 females, 5 males); one in teens, one in twenties, two in their thirties, and the rest over 40	Not mentioned	Folliculitis, papules, and pustules, necrotic eschars, scars	Not mentioned	Pruritus, anxiety, depression; patients manipulated and excoriated the initial lesions (folliculitis) leading to crusting, necrosis and scarring	Propionibacterium acnes (primary lesion), Staphylococcus aureus (secondary lesions)	Acne necrotica	Doxepin (antidepressive, antipruritic effects) together with the appropriate antibiotic-dicloxacillin (if S. aureus positive) or trimethoprim sulfa (if culture negative); topical clindamycin in alcohol solution; amitriptyline in those who could not tolerate doxepin due to drowsiness	Satisfactory resolution within 2 to 4 weeks. Follow-up at 3 to 6 months: 9 patients-disease-free, 4-recrudescence
Whiting et al. [11] (original article)	4 males (mean age 61 years), 1 female (age 69 years); 1.4% of all cicatricial alopecia cases	Not mentioned	Chronic pock-like folliculitis	Back and sides of scalp, extending onto the neck	Painful and pruritic; chronic condition and recurs at irregular intervals	Not done	Acne necrotica	Antiseptic shampoo like povidine-iodine; topical erythromycin, clindamycin or mupirocin, systemic antibiotics-tetracycline, doxycycline, minocycline, sulfamethoxazole/trimethoprim; oral isotretinoin; intralesional triamcinolone acetonide suspension 5 mg/ml	Isotretinoin was mentioned as last resort, and intralesional triamcinolone as the most effective treatment for persistent lesions
Pitney et al. [3] (case series)	47 patients (35 females, 12 males); average age 55 years (range: 21–93 years)	Not mentioned	Umbilicated inflammatory erythematous, follicular papulonodules, which healed with scarring or hypopigmentation	Predominantly scalp, head, and neck Less commonly disseminated	Pruritic, painful; dermal hypersensitivity in 7 patients; chronic and cropping; stress exacerbations	Not done	Acne necrotica; 5 patterns: classic (varioliform), acne necrotica miliaris, head and neck micropapular, cape distribution, disseminate	Topical treatment	No response
								Doxycycline 100 mg daily or erythromycin estolate 800 mg bid; isotretinoin (if severe)	Significant improvement within weeks. Severely affected required constant medication to prevent continuous cropping.
Nikolic et al. [12] (case report)	63 years, male	6 months	Papules, papulopustules, with central necrosis, hemorrhagic crusts, residual varioliform scars, and scarring alopecia	Frontal hairline, face, and neck	Pruritus, burning sensation; appears as crops	Physiological flora	Acne necrotica (varioliformis)	Topical erythromycin 2% cream and benzoyl peroxide 4% wash suspension for 2 weeks	Remission after 2 weeks
Present case report	24 years, male	Not known	Erythematous papules, papulopustular lesions with umbilicated summits in few, crateriform scars	Entire scalp, supraciliary region, and bridge of nose	Mild seborrhea, anxiety; patient was unaware of the lesions in past due to absence of itching and pain	Physiological flora	Acne necrotica ‘varioliformis’ or necrotizing lymphocytic folliculitis	Doxycycline 100 mg daily	Partial remission after 4 weeks

Acne necrotica is usually located on the face, with a peculiar distribution along the hairline. In the present case, almost the entire scalp was covered with varioliform scars, rendering it the noteworthy “scar-studded appearance.” The umbilicated papulopustular lesions, varioliform scars, and the histolopathogical findings led us to the diagnosis of acne necrotica “varioliformis.”

However, the clinical characteristics of acne necrotica had been well described in the 20th century, paucity of the literature thereafter, particularly in Asian population, implies underdiagnosis due to diminished interest and awareness. We are reporting this case to create awareness among dermatologists and reappraise the under-recognized entity of acne necrotica.

Statement of Ethics

The authors state that written informed consent was taken from the patient for publication of the case details, including clinical and histopathological photographs. Ethical approval from the Institutional Ethical Committee was not required.

Conflict of Interest Statement

The authors have no conflicts of interests to declare.

Funding Sources

There were no external funding sources for the preparation of the manuscript.

Author Contributions

Dr. Shruti Sharma has contributed to the conception of work, review of literature, drafting, and editing of manuscript. The coauthors (Dr. Surabhi Dayal, Dr. Varsha Gowda V.M., Dr. Neha Dhankar, Dr. Rajesh L Pathi, and Dr. Kamal Aggarwal) have also made substantial contributions to the manuscript including the literature review, drafting, and editing of manuscript. All the authors have approved the final version to be submitted and have agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All the authors fulfill the ICMJE criteria for the authorship.